- ID:
- ivo://ia2.inaf.it/hosted/laurino2011/tap
- Title:
- Laurino et al 2011 Catalog of WGE photometric redshifts for SDSS candidate qsos and galaxies
- Short Name:
- wgesdsstap
- Date:
- 06 May 2024 08:19:45
- Publisher:
- IA2
- Description:
- The Sloan Digital Sky Survey (SDSS) has observed more than a quarter of the sky over eight years of operations, obtaining multicolor photometry and spectroscopy for ~ 1 million of galaxies. A catalog of photometric redshifts for ~ 2 millions quasars with magnitude r < 20.7 extracted from the SDSS DR7 dataset (D'Abrusco et al, 2009) is provided here. The photometric redshifts and the uncertainty of the estimates for each sources have been calculated using the Weak Gated Expert (WGE) method. The WGE (Laurino et al., submitted to MNRAS) is based on the exploitation of the spectroscopic redshifts for a subset of photometric sources and derives photometric redshifts through a combination of data mining techniques. This method can be applied to different classes of extragalactic sources and is scalable. A set of observational parameters used for the evaluation of photometric redshifts, the estimated photometric redshifts values and some of the most common observational parameters retrieved from the SDSS database have been included in the catalog for the sake of simplicity.
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- ID:
- ivo://geops.ipsl/__system__/services/registry
- Title:
- GEOPS/IPSL DaCHS Server Registry
- Short Name:
- GEOPS RG
- Date:
- 01 May 2024 01:20:18
- Publisher:
- The staff at the GEOPS/IPSL DaCHS Server
- Description:
- The publishing registry for the GEOPS/IPSL DaCHS Server.
- ID:
- ivo://lmd.jussieu/__system__/services/registry
- Title:
- DaCHS Server for LMD Registry
- Short Name:
- LMD RG
- Date:
- 19 Apr 2024 00:10:33
- Publisher:
- The staff at the DaCHS Server for LMD
- Description:
- The publishing registry for the DaCHS Server for LMD.
- ID:
- ivo://ov-gso/tsap/speconvol
- Title:
- Synthetic Spectra Convolution Service
- Short Name:
- speconvol
- Date:
- 03 Apr 2024 08:16:45
- Publisher:
- OV-GSO Virtual Observatory services
- Description:
- Convolution of normalized synthetic stellar spectra. Up to 3 successive convolutions are allowed on a adjustable portion of a synthetic spectrum, in order to mimic an observable. These convolutions acount for macroturbulence velocity, rotational velocity and instrumental profile. Finally, the output can be Doppler-shifted in order to take into account a stellar radial velocity.
- ID:
- ivo://esavo/registry
- Title:
- EURO-VO Full Harvestable Registry
- Short Name:
- EURO-VO Registry
- Date:
- 07 Feb 2024 10:14:52
- Publisher:
- European Space Agency
- Description:
- EURO-VO Full Harvestable Registry.
- ID:
- ivo://padc.obspm.helio/__system__/services/registry
- Title:
- PADC TAP Server on voparis-tap-helio.obspm.fr Registry
- Short Name:
- PADC RG
- Date:
- 12 Dec 2023 13:58:39
- Publisher:
- The staff at the PADC TAP Server on voparis-tap-helio.obspm.fr
- Description:
- The publishing registry for the PADC TAP Server on voparis-tap-helio.obspm.fr.
- ID:
- ivo://padc.obspm.maser/__system__/services/registry
- Title:
- PADC TAP Server on voparis-tap-maser.obspm.fr Registry
- Short Name:
- PADC RG
- Date:
- 13 Nov 2023 15:39:14
- Publisher:
- The staff at the PADC TAP Server on voparis-tap-maser.obspm.fr
- Description:
- The publishing registry for the PADC TAP Server on voparis-tap-maser.obspm.fr.
- ID:
- ivo://padc.obspm.astro/__system__/services/registry
- Title:
- PADC TAP Server on voparis-tap-astro.obspm.fr Registry
- Short Name:
- PADC RG
- Date:
- 13 Nov 2023 15:36:14
- Publisher:
- The staff at the PADC TAP Server on voparis-tap-astro.obspm.fr
- Description:
- The publishing registry for the PADC TAP Server on voparis-tap-astro.obspm.fr.
- ID:
- ivo://padc.obspm.planeto/__system__/services/registry
- Title:
- PADC TAP Server on voparis-tap-planeto.obspm.fr Registry
- Short Name:
- PADC Reg
- Date:
- 13 Nov 2023 15:18:09
- Publisher:
- The staff at the PADC TAP Server on voparis-tap-planeto.obspm.fr
- Description:
- The publishing registry for the PADC TAP Server on voparis-tap-planeto.obspm.fr.
- ID:
- ivo://padc.obspm.he/__system__/services/registry
- Title:
- PADC TAP Server on voparis-tap-he.obspm.fr Registry
- Short Name:
- PADC RG
- Date:
- 12 Nov 2023 18:53:31
- Publisher:
- The staff at the PADC TAP Server on voparis-tap-he.obspm.fr
- Description:
- The publishing registry for the PADC TAP Server on voparis-tap-he.obspm.fr.
- ID:
- ivo://pds-ppi/__system__/services/registry
- Title:
- PDS-PPI VO server Registry
- Short Name:
- PDS-PPI RG
- Date:
- 09 Nov 2023 18:08:40
- Publisher:
- The staff at the PDS-PPI VO server
- Description:
- The publishing registry for the PDS-PPI VO server.
- ID:
- ivo://bira-iasb/__system__/services/registry
- Title:
- VESPA PA team server Registry
- Short Name:
- BIRA-IASB Reg
- Date:
- 28 Oct 2023 16:51:39
- Publisher:
- The staff at the VESPA PA team server
- Description:
- The publishing registry for the VESPA PA team server.
13. KSB-ROB Registry
- ID:
- ivo://ksb-orb.dc/__system__/services/registry
- Title:
- KSB-ROB Registry
- Short Name:
- KSB-ORB RG
- Date:
- 27 Oct 2023 11:02:10
- Publisher:
- The staff at the KSB-ROB
- Description:
- The publishing registry for the KSB-ROB.
- ID:
- ivo://fai.kz/__system__/services/registry
- Title:
- FAI archives Registry
- Short Name:
- FAI NVO DC RG
- Date:
- 10 Oct 2023 11:48:20
- Publisher:
- The staff at the FAI archives
- Description:
- The publishing registry for the FAI archives.
- ID:
- ivo://jvo/isas/darts/irts/IRTS-MIRS_Catalogue_2.1
- Title:
- IRTS MIRS Point Source Catalogue
- Short Name:
- IRTS_MIRS_PSC
- Date:
- 09 Sep 2023 00:57:23
- Publisher:
- JVO
- Description:
- IThe Japanese satellite-borne infrared telescope, the Infrared Telescope in Space (IRTS), surveyed about 7 per-cent of the entire sky in the infrared wavelengths from 1.4 to 700 um. The IRTS consists of a 15 cm telescope cooled with superfluid liquid helium, and is installed on board the Space Flyer Unit (SFU) spacecraft. The SFU was launched on 1995 March 18 UT. The sky survey by the IRTS started on March 29 UT, and was completed on April 25 UT after exhausting its liquid helium. The four focal-plane instruments were on board. The Mid-Infrared Spectrometer (MIRS) covered 4.5 to 11.7 um by 32 spectral channels with the resolution of Δλ = 0.23-0.36 um. The MIRS point source catalog contains spectra of 536 sources. Many of the detected sources are mas-losing stars. A few HII regions and one asteroid 01 Ceres are included.
- ID:
- ivo://jvo/isas/darts/irts/IRTS-NIRS_Catalogue_1.3
- Title:
- IRTS NIRS Point Source Catalogue
- Short Name:
- IRTS_NIRS_PSC
- Date:
- 09 Sep 2023 00:56:29
- Publisher:
- JVO
- Description:
- The Japanese satellite-borne infrared telescope, the Infrared Telescope in Space (IRTS), surveyed about 7 per-cent of the entire sky in the infrared wavelengths from 1.4 to 700 μm. The IRTS consists of a 15 cm telescope cooled with superfluid liquid helium, and is installed on board the Space Flyer Unit (SFU) spacecraft. The SFU was launched on 1995 March 18 UT. The sky survey by the IRTS started on March 29 UT, and was completed on April 25 UT after exhausting its liquid helium. The four focal-plane instruments were on board. The Near-Infrared Spectrometer (NIRS) covered 1.4 to 4.0 μm by 24 spectral channels with the resolution of Δλ = 0.13 μm. The complete level of the catalog is 10?20 Jy for the entire wavelength range. The NIRS point source catalog contains spectra of 14,223 sources in which 4,002 sources are in good quality. Late-type stars, normal stars, and other red objects are included.
- ID:
- ivo://aip.gavo.org/__system__/services/registry
- Title:
- AIP DaCHS Registry
- Short Name:
- AIP GAVO RG
- Date:
- 24 Aug 2023 11:45:33
- Publisher:
- The staff at the AIP DaCHS
- Description:
- The publishing registry for the AIP DaCHS.
- ID:
- ivo://jvo/isas/darts/akari/AKARI-IRC_Spectrum_Pointed_SlitlessMIR_spectrum_1.0
- Title:
- AKARI/IRC MIR-S slit-less spectroscopic catalogue
- Short Name:
- AKARI_IRC_SPEC_V1
- Date:
- 07 Feb 2023 00:55:14
- Publisher:
- JVO
- Description:
- A catalogue of mid-infrared slit-less spectra (5.5-12.5 ?m) extracted from the AKARI/IRC MIR-S spectroscopic observation data. All 886 MIR-S spectroscopic data obtained in Phases 1&2 are analyzed, and 862 spectra of 604 individual sources that are little contaminated by nearby sources are catalogued. We also present a 9 ?m point source catalogue generated as a by-product. The point source catalogue contains 42,387 sources brighter than 0.3 mJy.
- ID:
- ivo://jvo/isas/darts/akari/AKARI-IRC_Spectrum_Pointed_GALPN_1.0
- Title:
- AKARI/IRC NIR Spectral Atlas of Galactic Planetary Nebulae
- Short Name:
- AKARI_IRC_SPEC_GALPN
- Date:
- 07 Feb 2023 00:54:25
- Publisher:
- JVO
- Description:
- This catalog contains near-infrared (2.5--5.0 micron) low-resolution (R ~ 100) spectra of 72 Galactic Planetary Nebulae (PNe), obtained with the InfraRed Camera (IRC) onboard the AKARI satellite in the post-helium phase. The objects were treated as almost point sources for the IRC. Grism spectroscopy was carried out in the 1-arcmin window. The near-infrared spectra were obtained in a slit-less mode without any flux loss due to a slit. The spectra show emission features including hydrogen recombination lines, helium recombination lines, the 3.3--3.5 micron hydrocarbon features, [MgIV] at 4.49 micron, and [ArVI] at 4.53 micron. This catalog also contains the intensity and equivalent width of these emission features measured by spectral fitting. The source list (source.dat) summarizes observations. As ancillary data, the magnitudes in the V- and Ks-band, the extinction at V-band toward the objects, and the effective temperature collected from literature are listed in another table (misc.dat). The intensities and the equivalent widths of the emission features are tabulated in different tables (intens.dat and equivw.dat). Each object is identified by the PNG ID (PNG) or an observation ID (Obs-ID). One-dimensional near-infrared spectra are stored in a directory (spc/). Each spectrum is identified by the observation ID.
- ID:
- ivo://jvo/isas/darts/akari/AKARI-IRC_Spectrum_Pointed_DiffuseSkyPatch_1.0
- Title:
- AKARI/IRC NIR Low-resolution Spectral Catalogue of Diffuse Sky Patches
- Short Name:
- AKARI_IRC_SPEC_DSP
- Date:
- 07 Feb 2023 00:53:40
- Publisher:
- JVO
- Description:
- This catalog contains the 278 low-resolution (R~20) near-infrared (1.8-5.3 micron) spectra of diffuse sky covering a wide range of galactic and ecliptic latitudes with the Infrared Camera (IRC) onboard AKARI before the exhaustion of liquid-helium (from September 2006 to May 2007). Advanced reduction methods specialized for the slit spectroscopy of diffuse sky spectra are developed for constructing this spectral catalog.
- ID:
- ivo://tohoku.univ.jp/__system__/services/registry
- Title:
- Tohoku University VO Server Registry
- Short Name:
- Tohoku Reg
- Date:
- 22 Jan 2023 00:00:06
- Publisher:
- The staff at the Tohoku University VO Server
- Description:
- The publishing registry for the Tohoku University VO Server.
- ID:
- ivo://jvo/isas/akari_dr1
- Title:
- AKARI Point Source Catalogues Public Release 1
- Short Name:
- AKARI_DR1
- Date:
- 08 Jan 2023 14:49:11
- Publisher:
- JVO
- Description:
- Akari is Japan's first dedicated infrared astronomical satellite (and the second infrared space mission following IRTS) launched on February 22, 2006. Akari's primary mission is to carry out the all-sky survey with the best sensitivity, spatial resolution and the widest wavelengths. The AKARI/FIS Bright Source Catalogue Version 1.0 provides the positions and fluxes of 427,071 point sources in the four far-infrared wavelengths centred at 65, 90, 140, and 160 um. The sensitivity in the 90 um band is about 0.55 Jy. The AKARI/IRC Point Source Catalogue Version 1.0 provides positions and fluxes of 870,973 sources (844,649 sources in 9um band and 194,551 sources in 18um band) in the Mid-Infrared wavelengths.
- ID:
- ivo://leibniz-kis/__system__/services/registry
- Title:
- KIS Science Data Centre Registry
- Short Name:
- KIS VO SDC RG
- Date:
- 06 Dec 2022 08:42:46
- Publisher:
- The staff at the KIS Science Data Centre
- Description:
- The publishing registry for the KIS Science Data Centre.
- ID:
- ivo://jvo/isas/darts/akari/AKARI-IRC_Spectrum_Pointed_SlitlessMIR_psc_1.0
- Title:
- AKARI/IRC MIR-S slit-less 9um point source catalogue
- Short Name:
- AKARI_IRC_SPEC_PSC_V1
- Date:
- 23 Aug 2022 05:23:32
- Publisher:
- JVO
- Description:
- This is a 9 um point source catalogue generated as a by-product of the "AKARI/IRC MIR-S slit-less spectroscopic catalogue". The point source catalogue contains 42,387 sources brighter than 0.3 mJy.
- ID:
- ivo://jvo/isas/darts/akari/AKARI-IRC_Catalogue_AllSky_ASTFLUX_1.0
- Title:
- AKARI Asteroid Flux Catalogue Version 1
- Short Name:
- AKARI_ASTEROID_V1
- Date:
- 23 Aug 2022 05:22:33
- Publisher:
- JVO
- Description:
- The AKARI Asteroid Flux Catalog contains photometric data of 5201 asteroids observed with the Infrared Camera (IRC) on board the Japanese infrared astronomical satellite AKARI. The catalog objects comprise the near-Earth asteroids, the main belt asteroids, the Cybeles, the Hildas, and the Jovian Trojan asteroids. The observations were performed by the all-sky survey in 9 or 18 micron bands as well as the slow-scan observations in 9 or 18 micron bands, and the pointed observations in 4, 7, 11, 15, and/or 24 micron bands.
- ID:
- ivo://latmos.ipsl/__system__/services/registry
- Title:
- LATMOS DaCHS server Registry
- Short Name:
- LATMOS RG
- Date:
- 02 May 2022 13:52:13
- Publisher:
- The staff at the LATMOS DaCHS server
- Description:
- The publishing registry for the LATMOS DaCHS server.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A188
- Title:
- 4XMM-DR9-HECATE-based ULX catalogue
- Short Name:
- J/A+A/659/A188
- Date:
- 25 Mar 2022 09:09:32
- Publisher:
- CDS
- Description:
- Ultraluminous X-ray sources (LX>1x10^39^erg/s, ULXs) are excellent probes for extreme accretion physics, star formation history in galaxies, and intermediate-mass black holes searches. As the sample size of X-ray data from modern observatories such as XMM-Newton and Chandra increases, producing extensive catalogues of ULXs and studying their collective properties has become both a possibility and a priority. Our aim is to build a clean updated ULX catalogue based on one of the most recent XMM-Newton X-ray serendipitous survey data releases, 4XMM-DR9, and the most recent and exhaustive catalogue of nearby galaxies, HECATE. We performed a preliminary population study to test if the properties of the expanded XMM-Newton ULX population are consistent with previous findings. We performed positional cross-matches between XMM-Newton sources and HECATE objects to identify host galaxies, and we used distance and luminosity arguments to identify ULX candidates. We flagged interlopers by finding known counterparts in external catalogues and databases such as Gaia DR2 SSDS, Pan-STARRS1, the NASA/IPAC Extragalactic Database, and SIMBAD. Source, galaxy and variability parameters from 4XMM-DR9, HECATE, and 4XMM-DR9s were used to study the spectral, abundances and variability properties of the ULX sample. We identify 779 ULX candidates, 94 of which hold LX>5x10^40^erg/s. Spiral galaxies are more likely to host ULXs. For early spiral galaxies the number of ULX candidates per star-forming rate is consistent with previous studies, while a significant ULX population in elliptical and lenticular galaxies also exists. Candidates hosted by late-type galaxies tend to present harder spectra and to undergo more extreme inter-observation variability than those hosted by early-type galaxies. Approximately 30 candidates with LX>1x10^41^erg/s are also identified, constituting the most interesting candidates for intermediate-mass black hole searches. We have built the largest ULX catalogue to date. Our results on the spectral and abundance properties of ULXs confirm the findings made by previous studies based on XMM-Newton and Chandra data, while our population-scale study on variability properties is unprecedented. Our study, however, provides limited insight into the properties of the brightest ULX candidates due to the small sample size. The expected growth of X-ray catalogues and potential future follow-ups will aid in drawing a clearer picture.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A183
- Title:
- MUSE-Wide+MUSE-Deep EWs of Lyman{alpha} emitters
- Short Name:
- J/A+A/659/A183
- Date:
- 25 Mar 2022 09:08:03
- Publisher:
- CDS
- Description:
- The hydrogen Lyman{alpha} line is often the only measurable feature in optical spectra of high-redshift galaxies. Its shape and strength are influenced by radiative transfer processes and the properties of the underlying stellar population. High equivalent widths of several hundred {AA} are especially hard to explain by models and could point towards unusual stellar populations, for example with low metallicities, young stellar ages, and a top-heavy initial mass function. Other aspects influencing equivalent widths are the morphology of the galaxy and its gas properties. The aim of this study is to better understand the connection between the Lyman{alpha} rest-frame equivalent width (EW0) and spectral properties as well as ultraviolet (UV) continuum morphology by obtaining reliable EW0 histograms for a statistical sample of galaxies and by assessing the fraction of objects with large equivalent widths. We used integral field spectroscopy from the Multi Unit Spectroscopic Explorer (MUSE) combined with broad-band data from the Hubble Space Telescope (HST) to measure EW0 . We analysed the emission lines of 1920 Lyman{alpha} emitters (LAEs) detected in the full MUSE-Wide (one hour exposure time) and MUSE-Deep (ten hour exposure time) surveys and found UV continuum counterparts in archival HST data. We fitted the UV continuum photometric images using the Galfit software to gain morphological information on the rest-UV emission and fitted the spectra obtained from MUSE to determine the double peak fraction, asymmetry, full-width at half maximum, and flux of the Lyman{alpha} line. The two surveys show different histograms of Lyman{alpha} EW0 . In MUSE-Wide, 20% of objects have EW0>240{AA}, while this fraction is only 11% in MUSE-Deep and ~=16% for the full sample. This includes objects without HST continuum counterparts (one-third of our sample), for which we give lower limits for EW0. The object with the highest securely measured EW0 has EW0=589+/-193{AA} (the highest lower limit being EW0=4464{AA}). We investigate the connection between EW0 and Lyman{alpha} spectral or UV continuum morphological properties. The survey depth has to be taken into account when studying EW0 distributions. We find that in general, high EW0 objects can have a wide range of spectral and UV morphological properties, which might reflect that the underlying causes for high EW0 values are equally varied.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A181
- Title:
- J-PLUS DR1 stellar param, and abundances
- Short Name:
- J/A+A/659/A181
- Date:
- 25 Mar 2022 09:03:05
- Publisher:
- CDS
- Description:
- The Javalambre Photometric Local Universe Survey (J-PLUS) has obtained precise photometry in twelve specially designed filters for large numbers of Galactic stars. Deriving their precise stellar atmospheric parameters and individual elemental abundances is crucial for studies of Galactic structure, and the assembly history and chemical evolution of our Galaxy. Our goal is to estimate not only stellar parameters (effective temperature, Teff, surface gravity, logg, and metallicity, [Fe/H]), but also [{alpha}/Fe] and four elemental abundances ([C/Fe], [N/Fe], [Mg/Fe], and [Ca/Fe]) using data from J-PLUS DR1. By combining recalibrated photometric data from J-PLUS DR1, Gaia DR2, and spectroscopic labels from LAMOST, we design and train a set of cost-sensitive neural networks, the CSNet, to learn the non-linear mapping from stellar colors to their labels. We have achieved precisions of {delta}Teff~55K, {delta}logg~0.15dex, and {delta}[Fe/H]~0.07dex, respectively, over a wide range of temperature, surface gravity, and metallicity. The uncertainties of the abundance estimates for [{alpha}/Fe] and the four individual elements are in the range 0.04-0.08 dex. We compare our parameter and abundance estimates with those from other spectroscopic catalogs such as APOGEE and GALAH, and find an overall good agreement. Conclusions. Our results demonstrate the potential of well-designed, high-quality photometric data for determinations of stellar parameters as well as individual elemental abundances. Applying the method to J-PLUS DR1, we have obtained the aforementioned parameters for about two million stars, providing an outstanding data set for chemo-dynamic analyses of the Milky Way.
- ID:
- ivo://CDS.VizieR/J/AJ/162/267
- Title:
- I-band light curve of OGLE-2019-BLG-1058 with KMTNet
- Short Name:
- J/AJ/162/267
- Date:
- 25 Mar 2022 06:06:33
- Publisher:
- CDS
- Description:
- We show that because the conditions for producing terrestrial microlens parallax (TPRX; i.e., a nearby disk lens) will also tend to produce a large lens-source relative proper motion ({mu}rel), source proper motion ({mu}S) measurements in general provide a strong test of TPRX signals, which Gould & Yee (2013) showed were an important probe of free-floating planet (FFP) candidates. As a case study, we report a single-lens/single-source microlensing event designated as OGLE-2019-BLG-1058. For this event, the short timescale (~2.5days) and very fast {mu}rel (~17.6mas/yr) suggest that this isolated lens is an FFP candidate located in the disk of our Galaxy. For this event, we find a TPRX signal consistent with a disk FFP, but at low significance. A direct measurement of the {mu}S shows that the large {mu}rel is due to an extreme {mu}S, and thus, the lens is consistent with being a very-low-mass star in the bulge and the TPRX measurement is likely spurious. By contrast, we show how a precise measurement of {mu}S with the mean properties of the bulge proper motion distribution would have given the opposite result; i.e., provided supporting evidence for an FFP in the disk and the TPRX measurement.
- ID:
- ivo://jive.eu/__system__/services/registry
- Title:
- EVN Data Archive Registry
- Short Name:
- EVN RG
- Date:
- 24 Mar 2022 13:12:16
- Publisher:
- The staff at the EVN Data Archive
- Description:
- The publishing registry for the EVN Data Archive.
- ID:
- ivo://CDS.VizieR/J/ApJ/904/14
- Title:
- Optical and NIR observation of SN (Ia) 2017cbv
- Short Name:
- J/ApJ/904/14
- Date:
- 24 Mar 2022 06:19:55
- Publisher:
- CDS
- Description:
- Supernova (SN) 2017cbv in NGC5643 is one of a handful of Type Ia supernovae (SNeIa) reported to have excess blue emission at early times. This paper presents extensive BVRIYJHKs-band light curves of SN2017cbv, covering the phase from -16 to +125days relative to B-band maximum light. The SN2017cbv reached a B-band maximum of 11.710{+/-}0.006mag, with a postmaximum magnitude decline of {Delta}m15(B)=0.990{+/-}0.013mag. The SN suffered no host reddening based on Phillips intrinsic color, the Lira-Phillips relation, and the CMAGIC diagram. By employing the CMAGIC distance modulus {mu}=30.58{+/-}0.05mag and assuming H0=72km/s/Mpc, we found that 0.73M{sun} 56Ni was synthesized during the explosion of SN2017cbv, which is consistent with estimates using reddening- and distance-free methods via the phases of the secondary maximum of the near-IR- (NIR-) band light curves. We also present 14 NIR spectra from -18 to +49 days relative to the B-band maximum light, providing constraints on the amount of swept-up hydrogen from the companion star in the context of the single degenerate progenitor scenario. No Pa{beta} emission feature was detected from our postmaximum NIR spectra, placing a hydrogen mass upper limit of 0.1M{sun}. The overall optical/NIR photometric and NIR spectral evolution of SN2017cbv is similar to that of a normal SN Ia, even though its early evolution is marked by a flux excess not seen in most other well-observed normal SNe Ia. We also compare the exquisite light curves of SN2017cbv with some Mch delayed detonation models and sub-Mch double detonation models.
- ID:
- ivo://CDS.VizieR/J/A+A/648/A82
- Title:
- Quasar 3C 345 at 18 cm with RadioAstron
- Short Name:
- J/A+A/648/A82
- Date:
- 23 Mar 2022 16:32:52
- Publisher:
- CDS
- Description:
- Supermassive black holes in the centres of radio-loud active galactic nuclei (AGN) can produce collimated relativistic outflows (jets). Magnetic fields are thought to play a key role in the formation and collimation of these jets, but the details are much debated. We study the innermost jet morphology and magnetic field strength in the AGN 3C 345 with an unprecedented resolution using images obtained within the framework of the key science programme on AGN polarisation of the Space VLBI mission RadioAstron. We observed the flat spectrum radio quasar 3C 345 at 1.6GHz on 2016 March 30 with RadioAstron and 18 ground-based radio telescopes in full polarisation mode. Our images, in both total intensity and linear polarisation, reveal a complex jet structure at 300{mu}as as angular resolution, corresponding to a projected linear scale of about 2pc or a few thousand gravitational radii. We identify the synchrotron self-absorbed core at the jet base and find the brightest feature in the jet 1.5 mas downstream of the core. Several polarised components appear in the Space VLBI images that cannot be seen from ground array-only images. Except for the core, the electric vector position angles follow the local jet direction, suggesting a magnetic field perpendicular to the jet. This indicates the presence of plane perpendicular shocks in these regions. Additionally, we infer a minimum brightness temperature at the largest uv-distances of 1.1x10^12^K in the source frame, which is above the inverse Compton limit and an order of magnitude larger than the equipartition value. This indicates locally efficient injection or re-acceleration of particles in the jet to counter the inverse Compton cooling or the geometry of the jet creates significant changes in the Doppler factor, which has to be >11 to explain the high brightness temperatures.
- ID:
- ivo://CDS.VizieR/J/A+A/646/A18
- Title:
- The Bok globule CB 26
- Short Name:
- J/A+A/646/A18
- Date:
- 23 Mar 2022 16:32:20
- Publisher:
- CDS
- Description:
- Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins. We study the physical structure and grain growth in the edge-on disk that surrounds the ~1Myr old low-mass (~0.55M_{sun}_) protostar embedded in the Bok Globule CB26 to examine how much grain growth has already occurred in the protostellar phase. We combine the SED between 0.9um and 6.4cm with high angular resolution continuum maps at 1.3, 2.9, and 8.1mm, and use the radiative transfer code RADMC-3D to conduct a detailed modelling of the dust emission from the disk and envelope of CB 26. We infer inner and outer disk radii of around 16au and 172+/-22au, respectively. The total gas mass in the disk is ~0.076M_{sun}_, which amounts to ~14% of the mass of the central star. The inner disk contains a compact free-free emission region, which could be related to either a jet or a photoevaporation region. The thermal dust emission from the outer disk is optically thin at mm wavelengths, while the emission from the inner disk midplane is moderately optically thick. Our best-fit radiative transfer models indicate that the dust grains in the disk have already grown to pebbles with diameters of the order of 10cm in size. Residual 8.1mm emission suggests the presence of even larger particles in the inner disk. For the optically thin mm dust emission from the outer disk, we derive a mean opacity slope of {beta}_mm_~=0.7+/-0.4, which is consistent with the presence of large dust grains. The presence of cm-sized bodies in the CB 26 disk indicates that solids grow rapidly already during the first million years in a protostellar disk. It is thus possible that Class II disks are already seeded with large particles and may contain even planetesimals.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A20
- Title:
- W Aql APEX spectrum
- Short Name:
- J/A+A/642/A20
- Date:
- 23 Mar 2022 16:31:40
- Publisher:
- CDS
- Description:
- W Aql is an asymptotic giant branch (AGB) star with an atmospheric elemental abundance ratio C/O~=0.98. It has previously been reported to have circumstellar molecular abundances intermediate between those of M-type and C-type AGB stars, which respectively have C/O<1 and C/O>1. This intermediate status is considered typical for S-type stars, although our understanding of the chemical content of their circumstellar envelopes is currently rather limited. We wish to assess the reported intermediate status of W Aql by analysing the line emission of molecules that have not been observed towards this star before. We have performed observations in the frequency range 159-268GHz with the SEPIA/B5 and PI230 instruments on the APEX telescope. We make abundance estimates through direct comparison to available spectra towards a number of well-studied AGB stars and based on rotational diagram analysis in the case of one molecule. From a compilation of our abundance estimates and those found in the literature for two M-type (R Dor, IK Tau), two S-type ({chi} Cyg, W Aql), and two C-type stars (V Aql, IRC +10 216), we conclude that W Aql's circumstellar environment appears considerably closer to that of a C-type AGB star than to that of an M-type AGB star. In particular, we detect emission from C_2_H, SiC_2_, SiN, and HC_3_N, molecules previously only detected towards the circumstellar environment of C-type stars. This conclusion, based on the chemistry of the gaseous component of the circumstellar environment, is further supported by reports in the literature on the presence of atmospheric molecular bands and spectral features of dust species which are typical for C-type AGB stars. Although our observations mainly trace species in the outer regions of the circumstellar environment, our conclusion matches closely that based on recent chemical equilibrium models for the inner wind of S-type stars: the atmospheric and circumstellar chemistry of S-type stars likely resembles that of C-type AGB stars much more closely than that of M-type AGB stars. Further observational investigation of the gaseous circumstellar chemistry of S-type stars is required to characterise its dependence on the atmospheric C/O. Non-equilibrium chemical models of the circumstellar environment of AGB stars need to address the particular class of S-type stars and the chemical variety that is induced by the range in atmospheric C/O.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A47
- Title:
- SPHERE and NaCo images of HD 19467B
- Short Name:
- J/A+A/639/A47
- Date:
- 23 Mar 2022 16:31:06
- Publisher:
- CDS
- Description:
- HD 19467 observations were performed with the VLT exoplanet imager SPHERE and the VLT adaptive optics camera NaCo to further characterize the spectral and orbital properties of the known T-type brown dwarf companion.
- ID:
- ivo://CDS.VizieR/J/A+A/639/A121
- Title:
- LkCa 15 and 2MASS J16100501-2132318 ALMa images
- Short Name:
- J/A+A/639/A121
- Date:
- 23 Mar 2022 16:30:37
- Publisher:
- CDS
- Description:
- We present high-resolution millimeter continuum ALMA observations of the disks around the T Tauri stars LkCa 15 and 2MASS J16100501-2132318 (hereafter, J1610). These transition disks host dust-depleted inner regions, which have possibly been carved by massive planets, and they are of prime interest to the study of the imprints of planet-disk interactions. While at moderate angular resolution, they appear as a broad ring surrounding a cavity, the continuum emission resolves into multiple rings at a resolution of ~60x40,mas (~7.5au for LkCa 15, ~6au for J1610) and ~7uJy/beam rms at 1.3mm. In addition to a broad extended component, LkCa 15 and J1610 host three and two narrow rings, respectively, with two bright rings in LkCa 15 being radially resolved. LkCa 15 possibly hosts another faint ring close to the outer edge of the mm emission. The rings look marginally optically thick, with peak optical depths of ~0.5 (neglecting scattering), in agreement with high angular resolution observations of full disks. We performed hydrodynamical simulations with an embedded, sub-Jovian-mass planet and show that the observed multi-ringed substructure can be qualitatively explained as the outcome of the planet-disk interaction. We note, however, that the choice of the disk cooling timescale alone can significantly impact the resulting gas and dust distributions around the planet, leading to different numbers of rings and gaps and different spacings between them. We propose that the massive outer disk regions of transition disks are favorable places for planetesimals, and possibly second-generation planet formation of objects with a lower mass than the planets carving the inner cavity (typically few M_Jup_), and that the annular substructures observed in LkCa~15 and J1610 may be indicative of planetary core formation within dust-rich pressure traps. Current observations are compatible with other mechanisms contributing to the origin of the observed substructures, in particular with regard to narrow rings generated (or facilitated) at the edge of the CO and N_2_ snowlines.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A29
- Title:
- 3C388 145, 392, 614, 1400 and 4850MHz images
- Short Name:
- J/A+A/638/A29
- Date:
- 23 Mar 2022 16:29:17
- Publisher:
- CDS
- Description:
- Restarted radio galaxies represent a unique tool to investigate the duty cycle of the jet activity in Active Galactic Nuclei. Due to a sharp discontinuity of the GHz spectral index distribution within its lobes, the radio galaxy 3C388 has for long being claimed to be a peculiar example of AGN with multi-epoch activity The goal of this work is to perform for the first time a spatially resolved study of the radio spectrum of this source down to MHz-frequencies, in order to investigate its radiative age and constrain its duty cycle. We have used new low frequency observations at 144MHz performed with the Low Frequency Array and at 350MHz performed with the Very Large Array combined with archival data at higher frequencies (614, 1400, 4850MHz). Results. We find that the spectral indices in the lower frequency range 144-614MHz have flatter values ({alpha}_low_~0.55-1.14) than those observed in the higher frequency range 1400-4850MHz ({alpha}_high_~0.75-1.57) but follow the same distribution across the lobes, with a systematic steepening towards the edges. However, the spectral shape throughout the source is not uniform and often deviates from standard models. This suggests that mixing of different particle populations is occurring, although it remains difficult to understand whether this is caused by observational limitations (insufficient spatial resolution and/or projection effects) or by the intrinsic presence of multiple particle populations, possibly related to the two different outbursts. By using single-injection radiative models we compute that the total source age is <~80Myr and that the duty cycle is about t_on_/t_tot_~60%, which is enough to prevent the intracluster medium from cooling according to X-ray estimates. While to date the radio spectral distribution of 3C388 remains a rare case among radio galaxies, multi-frequency surveys performed with new generation instruments will soon allow us to investigate whether more sources with the same characteristics do actually exist.
- ID:
- ivo://CDS.VizieR/J/A+A/628/A69
- Title:
- LOFAR 143MHz images of 3C 236
- Short Name:
- J/A+A/628/A69
- Date:
- 23 Mar 2022 16:28:49
- Publisher:
- CDS
- Description:
- We have examined the giant radio galaxy 3C 236 using LOFAR at 143MHz down to an angular resolution of 7 arcseconds, in combination with observations at higher frequencies. We used the low frequency data to derive spectral index maps with the highest resolution yet at these low frequencies. We confirm a previous detection of an inner hotspot in the north-west lobe and for the first time observe that the south-east lobe hotspot is in fact a triple hotspot, which may point to an intermittent source activity. Also, the spectral index map of 3C 236 shows that the spectral steepening at the inner region of the northern lobe is prominent at low frequencies. The outer regions of both lobes show spectral flattening, in contrast with previous high frequency studies. We derive spectral age estimates for the lobes, as well as particle densities of the IGM at various locations. We propose that the morphological differences between the lobes are driven by variations in the ambient medium density as well as the source activity history.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A94
- Title:
- FS Tau B two epoch spectro-imagery
- Short Name:
- J/A+A/627/A94
- Date:
- 23 Mar 2022 16:28:17
- Publisher:
- CDS
- Description:
- Herbig-Haro (HH) flows exhibit a large variety of morphological and kinematical structures such as bow shocks, Mach disks, and deflection shocks. Both proper motion (PM) and radial velocity investigations are essential to understand the physical nature of such structures. We investigate the kinematics and PM of spectrally separated structures in the FS Tau B HH flow. Collating these data makes it possible to understand the origin of these structures and to explain the unusual behavior of the jet. On the other hand, the study of emission profiles in the associated reflection nebulae allows us to consider the source of the outflow both from edge-on and pole-on points of view. We present the observational results obtained with the 6 m telescope at the Special Astrophysical Observatory of the Russian Academy of Sciences using the SCORPIO multimode focal reducer with a scanning Fabry-Perot interferometer. Two epochs of the observations of the FS Tau B region in H{alpha} emission (2001 and 2012) allowed us to measure the PM of the spectrally separated inner structures of the jet. In addition to already known emission structures in the FS Tau B system, we discover new features in the extended part of the jet and in the counter-jet. Moreover, we reveal a new HH knot in the HH 276 independent outflow system and point out its presumable source. In the terminal working surface of the jet, structures with different radial velocities have PMs of the same value. This result can be interpreted as the direct observation of bow-shock and Mach disk regions. A bar-like structure, located southwest from the source demonstrates zero PM and can be considered as one more example of deflection shock. An analysis of H{alpha} profiles in the reflection nebulae R1 and R3 indicates the uniqueness of this object, which can be studied in pole-on and edge-on directions simultaneously.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A106
- Title:
- HI observations of AT 2018cow
- Short Name:
- J/A+A/627/A106
- Date:
- 23 Mar 2022 16:27:48
- Publisher:
- CDS
- Description:
- Unusual stellar explosions represent an opportunity to learn about both stellar and galaxy evolution. Mapping the atomic gas in host galaxies of such transients can lead to an understanding of the conditions triggering them. We provide resolved atomic gas observations of the host galaxy, CGCG137-068, of the unusual, poorly-understood transient AT2018cow searching for clues to understand its nature. We test whether it is consistent with a recent inflow of atomic gas from the intergalactic medium, as suggested for host galaxies of gamma-ray bursts (GRBs) and some supernovae (SNe). We observed the HI hyperfine structure line of the AT2018cow host with the Giant Metrewave Radio Telescope. There is no unusual atomic gas concentration near the position of AT2018cow. The gas distribution is much more regular than those of GRB/SN hosts. The AT2018cow host has an atomic gas mass lower by 0.24dex than predicted from its star formation rate (SFR) and is at the lower edge of the galaxy main sequence. In the continuum we detected the emission of AT2018cow and of a star-forming region in the north-eastern part of the bar (away from AT2018cow). This region hosts a third of the galaxy's SFR. The absence of atomic gas concentration close to AT2018cow, along with a normal SFR and regular HI velocity field, sets CGCG137-068 apart from GRB/SN hosts studied in HI. The environment of AT2018cow therefore suggests that its progenitor may not have been a massive star. Our findings are consistent with an origin of the transient that does not require a connection between its progenitor and gas concentration or inflow: an exploding low-mass star, a tidal disruption event, a merger of white dwarfs, or a merger between a neutron star and a giant star. We interpret the recently reported atomic gas ring in CGCG137-068 as a result of internal processes connected with gravitational resonances caused by the bar.
- ID:
- ivo://CDS.VizieR/J/A+A/618/A154
- Title:
- SPHERE/ZIMPOL (89) Julia images
- Short Name:
- J/A+A/618/A154
- Date:
- 23 Mar 2022 16:27:22
- Publisher:
- CDS
- Description:
- The vast majority of the geophysical and geological constraints (e.g., internal structure, cratering history) for main-belt asteroids have so far been obtained via dedicated interplanetary missions (e.g., ESA Rosetta, NASA Dawn). The high angular resolution of SPHERE/ZIMPOL, the new-generation visible adaptive-optics camera at ESO VLT, implies that these science objectives can now be investigated from the ground for a large fraction of D>=100km main-belt asteroids. The sharp images acquired by this instrument can be used to accurately constrain the shape and thus volume of these bodies (hence density when combined with mass estimates) and to characterize the distribution and topography of D>=30km craters across their surfaces. Here, via several complementary approaches, we evaluated the recently proposed hypothesis that the S-type asteroid (89) Julia is the parent body of a small compact asteroid family that formed via a cratering collisional event. We observed (89) Julia with VLT/SPHERE/ZIMPOL throughout its rotation, derived its 3D shape, and performed a reconnaissance and characterization of the largest craters. We also performed numerical simulations to first confirm the existence of the Julia family and to determine its age and the size of the impact crater at its origin. Finally, we utilized the images/3D shape in an attempt to identify the origin location of the small collisional family. On the one hand, our VLT/SPHERE observations reveal the presence of a large crater (D~75km) in Julia's southern hemisphere. On the other hand, our numerical simulations suggest that (89) Julia was impacted 30-120Myrs ago by a D~8km asteroid, thereby creating a D>=60km impact crater at the surface of Julia. Given the small size of the impactor, the obliquity of Julia and the particular orientation of the family in the (a,i) space, the imaged impact crater is likely to be the origin of the family. New doors into ground-based asteroid exploration, namely, geophysics and geology, are being opened thanks to the unique capabilities of VLT/SPHERE. Also, the present work may represent the beginning of a new era of asteroid-family studies. In the fields of geophysics, geology, and asteroid family studies, the future will only get brighter with the forthcoming arrival of 30-40m class telescopes like ELT, TMT, and GMT.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A148
- Title:
- NGC 6397 stars MUSE spectra
- Short Name:
- J/A+A/588/A148
- Date:
- 23 Mar 2022 16:26:54
- Publisher:
- CDS
- Description:
- We demonstrate the high multiplex advantage of crowded field 3D spectroscopy with the new integral field spectrograph MUSE by means of a spectroscopic analysis of more than 12000 individual stars in the globular cluster NGC 6397. The stars are deblended with a point spread function fitting technique, using a photometric reference catalogue from HST as prior, including relative positions and brightnesses. This catalogue is also used for a first analysis of the extracted spectra, followed by an automatic in-depth analysis via a full-spectrum fitting method based on a large grid of PHOENIX spectra. We analysed the largest sample so far available for a single globular cluster of 18 932 spectra from 12 307 stars in NGC 6397. We derived a mean radial velocity of v_rad_=17.84+/-0.07km/s and a mean metallicity of [Fe/H]=-2.120+/-0.002, with the latter seemingly varying with temperature for stars on the red giant branch (RGB). We determine Teff and [Fe/H] from the spectra, and log g from HST photometry. This is the first very comprehensive Hertzsprung-Russell diagram (HRD) for a globular cluster based on the analysis of several thousands of stellar spectra, ranging from the main sequence to the tip of the RGB. Furthermore, two interesting objects were identified; one is a post-AGB star and the other is a possible millisecond-pulsar companion.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A167
- Title:
- Cepheid Period-Wesenheit-Metallicity relation
- Short Name:
- J/A+A/659/A167
- Date:
- 23 Mar 2022 15:18:20
- Publisher:
- CDS
- Description:
- Classical Cepheids (DCEPs) represent a fundamental tool to calibrate the extragalactic distance scale. However, they are also powerful stellar population tracers, in the context of Galactic studies. The forthcoming Data Release 3 (DR3) of the Gaia mission will allow us to study with unprecedented detail the structure, the dynamics and the chemical properties of the Galactic disc, and in particular of the spiral arms, where most Galactic DCEPs reside. In this paper we aim at quantifying the metallicity dependence of the Galactic DCEPs Period-Wesenheit (PWZ) relation in the Gaia bands. We adopt a sample of 499 DCEPs with metal abundances from high-resolution spectroscopy, in conjunction with Gaia Early Data Release 3 parallaxes and photometry to calibrate a PWZ relation in the Gaia bands. We find a significant metallicity term, of the order of -0.5mag/dex, which is larger than the values measured in the NIR bands by different authors. Our best PWZ relation is W=(-5.988+/-0.018)-(3.176+/-0.044)(logP-1.0)-(0.520+/-0.090)[Fe/H]. We validate our PWZ relations by using the distance to the Large Magellanic Cloud as a benchmark, finding a very good agreement with the geometric distance provided by eclipsing binaries. As an additional test, we evaluate the metallicity gradient of the young Galactic disc, finding -0.0527+/-0.0022dex/kpc, in very good agreement with previous results.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A166
- Title:
- Catalogue of Cosmic Filaments
- Short Name:
- J/A+A/659/A166
- Date:
- 23 Mar 2022 15:17:04
- Publisher:
- CDS
- Description:
- In this work we present a new catalogue of cosmic filaments obtained from the latest Sloan Digital Sky Survey (SDSS) public data. In order to detect filaments, we implement a version of the Subspace-Constrained Mean-Shift algorithm that is boosted by machine learning techniques. This allows us to detect cosmic filaments as one-dimensional maxima in the galaxy density distribution. Our filament catalogue uses the cosmological sample of SDSS, including Data Release 16, and therefore inherits its sky footprint (aside from small border effects) and redshift coverage. In particular, this means that, taking advantage of the quasar sample, our filament reconstruction covers redshifts up to z=2.2, making it one of the deepest filament reconstructions to our knowledge. We follow a tomographic approach and slice the galaxy data in 269 shells at different redshift. The reconstruction algorithm is applied to 2D spherical maps. The catalogue provides the position and uncertainty of each detection for each redshift slice. The quality of our detections, which we assess with several metrics, show improvement with respect to previous public catalogues obtained with similar methods. We also detect a highly significant correlation between our filament catalogue and galaxy cluster catalogues built from microwave observations of the Planck Satellite and the Atacama Cosmology Telescope.
- ID:
- ivo://org.gavo.dc/__system__/services/registry
- Title:
- GAVO Data Center Registry
- Short Name:
- GAVO DC Reg
- Date:
- 23 Mar 2022 13:13:16
- Publisher:
- GAVO Heidelberg Data Center
- Description:
- The publishing registry for the GAVO Heidelberg Data Center. On request, we also host other registry records. Use the contact address for more information.
- ID:
- ivo://org.gavo.dc/misc/adqlcourse
- Title:
- The GAVO ADQL Course
- Short Name:
- GAVO ADQL course
- Date:
- 23 Mar 2022 13:13:04
- Publisher:
- The GAVO DC team
- Description:
- A short course on the VO's SQL-like query language, the Astronomical Data Query Language. It also covers basic operation of some TAP user agents. It is available as a multipage HTML rendering for online perusal as well as a one-file PDF.
- ID:
- ivo://org.gavo.dc/misc/adqlref
- Title:
- The GAVO ADQL Reference Card
- Short Name:
- GAVO ADQL ref
- Date:
- 23 Mar 2022 13:13:04
- Publisher:
- The GAVO DC team
- Description:
- GAVO's ADQL reference card briefly gives an overview of the SQL dialect used in the VO. It is available as a PDFfile and as Scribus source under the CC-BY license.
- ID:
- ivo://CDS.VizieR/J/A+A/638/L15
- Title:
- (16) Psyche. VLT/SPHERE images and shape models
- Short Name:
- J/A+A/638/L15
- Date:
- 23 Mar 2022
- Publisher:
- CDS
- Description:
- Asteroid (16) Psyche is the largest M-type asteroid in the main belt and the target of the NASA Psyche mission. It is also the only asteroid of this size (D>200km) known to be metal rich. Although various hypotheses have been proposed to explain the rather unique physical properties of this asteroid, a perfect understanding of its formation and bulk composition is still missing. We aim to refine the shape and bulk density of (16) Psyche and to perform a thorough analysis of its shape to better constrain possible formation scenarios and the structure of its interior. We obtained disk-resolved VLT/SPHERE/ZIMPOL images acquired within our ESO large program (ID 199.C-0074), which complement similar data obtained in 2018. Both data sets offer a complete coverage of Psyche's surface. These images were used to reconstruct the three-dimensional (3D) shape of Psyche with two independent shape modeling algorithms (MPCD and ADAM). A shape analysis was subsequently performed, including a comparison with equilibrium figures and the identification of mass deficit regions. Our 3D shape along with existing mass estimates imply a density of 4.20+/-0.60g/cm^3, which is so far the highest for a solar system object following the four telluric planets. Furthermore, the shape of Psyche presents small deviations from an ellipsoid, that is, prominently three large depressions along its equator. The flatness and density of Psyche are compatible with a formation at hydrostatic equilibrium as a Jacobi ellipsoid with a shorter rotation period of ~3h. Later impacts may have slowed down Psyche's rotation, which is currently ~4.2h, while also creating the imaged depressions. Our results open the possibility that Psyche acquired its primordial shape either after a giant impact while its interior was already frozen or while its interior was still molten owing to the decay of the short-lived radionuclide ^26^Al.
- ID:
- ivo://CDS.VizieR/J/AJ/162/63
- Title:
- ZTF light curve of 51 stars in 12 globular clusters
- Short Name:
- J/AJ/162/63
- Date:
- 21 Mar 2022 11:55:52
- Publisher:
- CDS
- Description:
- In this work, we aimed to derive the gri-band period-luminosity (PL) and period-luminosity-color (PLC) relations for late-type contact binaries, for the first time, located in globular clusters, using the homogeneous light curves collected by the Zwicky Transient Factory (ZTF). We started with 79 contact binaries in 15 globular clusters, and retained 30 contact binaries in 10 globular clusters that have adequate numbers of data points in the ZTF light curves and are unaffected by blending. Magnitudes at mean and maximum light of these contact binaries were determined using a fourth-order Fourier expansion, while extinction corrections were done using the Bayerstar2019 3D reddening map together with adopting the homogeneous distances to their host globular clusters. After removing early-type and "anomaly" contact binaries, our derived gri-band PL and period-Wesenheit (PW) relations exhibited a much larger dispersion with large errors on the fitted coefficients. Nevertheless, the gr-band PL and PW relations based on this small sample of contact binaries in globular clusters were consistent with those based on a larger sample of nearby contact binaries. Good agreements of the PL and PW relations suggested both samples of contact binaries in the local Solar neighborhood and in the distant globular clusters can be combined and used to derive and calibrate the PL, PW, and PLC relations. The final derived gr-band PL, PW, and PLC relations were much improved over those based on the limited sample of contact binaries in the globular clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A17
- Title:
- Post-common-envelope PN and mol. mass
- Short Name:
- J/A+A/658/A17
- Date:
- 21 Mar 2022 09:39:31
- Publisher:
- CDS
- Description:
- Most planetary nebulae (PNe) show beautiful, axisymmetric morphologies despite their progenitor stars being essentially spherical. Close binarity is widely invoked to help eject an axisymmetric nebula, after a brief phase of engulfment of the secondary within the envelope of the Asymptotic Giant Branch (AGB) star, known as the common envelope (CE). The evolution of the AGB would thus be interrupted abruptly, its still quite massive envelope being rapidly ejected to form the PN, which a priori would be more massive than a PN coming from the same star, were it single. We aim at testing this hypothesis by investigating the ionised and molecular masses of a sample consisting of 21 post-CE PNe, roughly one fifth of the known total population of these objects, and comparing them to a large sample of 'regular' (i.e. not known to arise from close-binary systems) PNe. We have gathered data on the ionised and molecular content of our sample from the literature, and carried out molecular observations of several previously unobserved objects. We derive the ionised and molecular masses of the sample by means of a systematic approach, using tabulated, dereddened H-beta fluxes for finding the ionised mass, and ^12^CO J=2-1 and J=3-2 observations for estimating the molecular mass. There is a general lack of molecular content in post-CE PNe. Our observations only reveal molecule-rich gas around NGC 6778, distributed into a low-mass, expanding equatorial ring lying beyond the ionised broken ring previously observed in this nebula. The only two other objects showing molecular content (from the literature) are NGC 2346 and NGC 7293. Once we derive the ionised and molecular masses, we find that post-CE PNe arising from Single-Degenerate (SD) systems are just as massive, on average, as the 'regular' PNe sample, whereas post-CE PNe arising from Double-Degenerate (DD) systems are considerably more massive, and show substantially larger linear momenta and kinetic energy than SD systems and `regular' PNe. Reconstruction of the CE of four objects, for which a wealth of data on the nebulae and complete orbital parameters are available, further suggests that the mass of SD nebulae actually amounts to a very small fraction of the envelope of their progenitor stars. This leads to the uncomfortable question of where the rest of the envelope is and why we cannot detect it in the stars' vicinity, thus raising serious doubts on our understanding of these intriguing objects.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A21
- Title:
- Infrared-radio relation in the local universe
- Short Name:
- J/A+A/658/A21
- Date:
- 21 Mar 2022 09:38:59
- Publisher:
- CDS
- Description:
- The Square Kilometer Array (SKA) is expected to detect high-redshift galaxies with star formation rates (SFRs) up to two orders of magnitude lower than Herschel surveys and will thus boost the ability of radio astronomy to study extragalactic sources. The tight infrared-radio correlation offers the possibility of using radio emission as a dust-unobscured star formation diagnostic. However, the physics governing the link between radio emission and star formation is poorly understood, and recent studies have pointed to differences in the exact calibration required when radio is to be used as a star formation tracer. We improve the calibration of the relation of the local radio luminosity-SFR and to test whether there are nonlinearities in it. We used a sample of Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) sources and investigated their radio luminosity, which was derived using the NRAO VLA Sky Survey (NVSS) and Faint Images of the Radio Sky at Twenty-cm (FIRST) maps. We stacked the bins of infrared luminosity and SFR and accounted for bins with no detections in the stacked images using survival analysis fitting. This approach was tested using Monte Carlo simulations. After removing sources from the sample that have excess radio emission, which is indicative of nuclear radio activity, we found no deviations from linearity of the mean relations between radio luminosity and either SFR or infrared luminosity. We analyzed the link between radio emission and SFR or infrared luminosity using a local sample of star-forming galaxies without evidence of nuclear radio activity and found no deviations from linearity, although our data are also consistent with the small nonlinearity reported by some recent analyses. The normalizations of these relations are intermediate between those reported by earlier works.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A136
- Title:
- OMC-2 FIR4 fits images
- Short Name:
- J/A+A/657/A136
- Date:
- 21 Mar 2022 09:38:35
- Publisher:
- CDS
- Description:
- Isotopic fractionation is an important tool for investigating the chemical history of our Solar System. In particular, the isotopic fraction of nitrogen (^14^N/^15^N) is lower in comets and other pristine Solar System bodies with respect to the value measured for the protosolar nebula, suggesting a local chemical enrichment of ^15^N during the formation of the Solar System. Therefore, interferometric studies of nitrogen fractionation in Solar System precursors are needed for us to obtain clues about our astrochemical origins. In this work we have investigated the variation in the ^14^N/^15^N ratio in one of the closest analogues of the environment in which the Solar System was born: the protocluster OMC-2 FIR4. We present the first comparison at high angular resolution between HCN and N_2_H^+^ using interferometric data. We analysed observations of the HCN isotopologues H^13^CN and HC^15^N in the OMC-2 FIR4 protocluster. Specifically, we observed the transitions H^13^CN (1-0) and HC^15^N (1-0) with the NOrthern Extended Millimeter Array (NOEMA) within the context of the IRAM Seeds Of Life In Space (SOLIS) Large Program. We combined our results with analysis of archival data obtained with the Atacama Large Millimeter Array (ALMA) of N_2_H^+^ and its ^15^N isotopologues. Our results show a small regional variation in the ^14^N/^15^N ratio for HCN, from ~250 to 500. The ratios in the central regions of FIR4, where the candidate protostars are located, are largely consistent with one another and within that range (~300). They also show little variation from the part of the protocluster known to harbour a high cosmic-ray ionisation rate to the portion with a lower rate. We also found a small variation in the ^14^N/^15^N ratio of N_2_H^+^ across different regions, from ~200 to ~400. These results suggest that local changes in the physical parameters occurring on the small linear scales probed by our observations in the protocluster do not seem to affect the ^14^N/^15^N ratio in either HCN or N_2_H^+^ and hence that this is independent of the molecule used. Moreover, the high level of irradiation due to cosmic rays does not affect the N fractionation either.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A125
- Title:
- KI diagnostic capabilities for M dwarfs
- Short Name:
- J/A+A/657/A125
- Date:
- 21 Mar 2022 09:37:41
- Publisher:
- CDS
- Description:
- The strong KI doublet near 7700{AA} and another doublet near 12500{AA} are studied in a sample of 324 M dwarfs using CARMENES spectra. For the optical doublet we use only the red line, since the blue line is often contaminated by telluric correction artefacts. Both doublets have a dominant photospheric component in inactive stars and can be used as tracers of effective temperature and gravity. For M dwarfs later than M5.0V the optical doublet lines develop an emission core. The line is often correlated to H{alpha} for stars with H{alpha} in emission and anticorrelated for stars with H{alpha} in absorption. The near-infrared doublet lines very rarely show correlation/anti-correlation to H{alpha}.
- ID:
- ivo://CDS.VizieR/J/A+A/657/L15
- Title:
- Q1700-MD94 CI(1-0) datacube with NOEMA
- Short Name:
- J/A+A/657/L15
- Date:
- 21 Mar 2022 09:37:17
- Publisher:
- CDS
- Description:
- We use a combination of new NOrthern Extended Millimeter Array (NOEMA) observations of the pair of [CI] transitions, the CO(7-6) line, and the dust continuum, in addition to ancillary CO(1-0) and CO(3-2) data, to study the molecular gas properties of Q1700-MD94, a massive, main-sequence galaxy at z~2. We find that for a reasonable set of assumptions for a typical massive star-forming galaxy, the CO(1-0), the [CI](1-0) and the dust continuum yield molecular gas masses that are consistent within a factor of ~2. The global excitation properties of the molecular gas as traced by the [CI] and CO transitions are similar to those observed in other massive, star-forming galaxies at z~2. Our large velocity gradient (LVG) modeling using RADEX of the CO and [CI] spectral line energy distributions (SLEDs) suggests the presence of relatively warm (Tkin=41K), dense (n_H2_=8x10^3^cm^-3^) molecular gas, comparable to the high-excitation molecular gas component observed in main-sequence, star-forming galaxies at z~1. The galaxy size in the CO(1-0) and CO(7-6) line emission are comparable, which suggests that the highly-excited molecular gas is distributed throughout the disk powered by intense star formation activity. To confirm this scenario will require spatially resolved observations of the CO and [CI] lines which can now be obtained with NOEMA upgraded capabilities.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/104
- Title:
- IR high-res. sp. of hot cores of AFGL2591 & AFGL2136
- Short Name:
- J/ApJ/900/104
- Date:
- 21 Mar 2022 09:36:08
- Publisher:
- CDS
- Description:
- We have performed a high-resolution 4-13{mu}m spectral survey of the hot molecular gas associated with the massive protostars AFGL 2591 and AFGL 2136, utilizing the Echelon Cross Echelle Spectrograph (EXES) on board the Stratospheric Observatory for Infrared Astronomy, and the iSHELL instrument and Texas EchelonCross Echelle Spectrograph (TEXES) on the NASA Infrared Telescope Facility (IRTF). Here we present the results of this survey with analysis of CO, HCN, C2H2, NH3, and CS, deriving the physical conditions for each species. Also from the IRTF, iSHELL data at 3{mu}m for AFGL 2591 are presented that show HCN and C2H2 in emission. In the EXES and TEXES data, all species are detected in absorption, and temperatures and abundances are found to be high (600K and 10^-6^, respectively). Differences of up to an order of magnitude in the abundances of transitions that trace the same ground-state level are measured for HCN and C2H2. The mid-infrared continuum is known to originate in a disk, hence we attribute the infrared absorption to arise in the photosphere of the disk. As absorption lines require an outwardly decreasing temperature gradient, we conclude that the disk is heated in the midplane by viscous heating due to accretion. We attribute the near-IR emission lines to scattering by molecules in the upper layers of the disk photosphere. The absorption lines trace the disk properties at 50 au where high-temperature gas-phase chemistry is taking place. Abundances are consistent with chemical models of the inner disk of Herbig disks.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A99
- Title:
- The rotational spectrum of glycinamide
- Short Name:
- J/A+A/657/A99
- Date:
- 21 Mar 2022 09:35:44
- Publisher:
- CDS
- Description:
- Glycinamide (NH_2_CH_2_C(O)NH_2_) is considered to be one of the possible precursors of the simplest amino acid glycine. Its only rotational spectrum reported so far has been in the cm-wave region on a laser-ablation generated supersonic expansion sample. The aim of this work is to extend the laboratory spectrum of glycinamide into the millimetre wave region to support its searches in the interstellar medium and to perform the first check for its presence in the high-mass star forming region Sagittarius B2(N). Glycinamide was synthesised chemically and was studied with broadband rotational spectroscopy in the 90-329 GHz region with the sample in slow flow at 50{deg}C. Tunneling across a low energy barrier between two symmetry equivalent configurations of the molecule resulted in splitting of each vibrational state and many perturbations in associated rotational energy levels, requiring careful coupled state fits for each vibrational doublet. We searched for emission of glycinamide in the imaging spectral line survey ReMoCA performed with the Atacama Large Millimetre/submillimetre Array toward Sgr B2(N). The astronomical spectra were analysed under the assumption of local thermodynamic equilibrium. We report the first analysis of the mm-wave rotational spectrum of glycinamide, resulting in fitting to experimental measurement accuracy of over 1200 assigned and measured transition frequencies for the ground state tunneling doublet, of many lines for tunneling doublets for two singly excited vibrational states, and determination of precise vibrational separation in each doublet. We did not detect emission from glycinamide in the hot molecular core Sgr B2(N1S). We derived a column density upper limit of 1.5x10^16^cm^-2^, which implies that glycinamide is at least seven times less abundant than aminoacetonitrile and 1.8 times less abundant than urea in this source.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A30
- Title:
- W51 North ALMA 1.3 and 3mm images
- Short Name:
- J/A+A/657/A30
- Date:
- 21 Mar 2022 09:31:18
- Publisher:
- CDS
- Description:
- The fragmentation process in massive star-forming regions is one of the contemporary problems in astrophysics, and several physical processes have been proposed to control the fragmentation including turbulence, magnetic field, rotation, stellar feedback, and gravity. However, the fragmentation process has been poorly studied at small spatial scales well below 1000AU. W51 IRS2 is a well known massive star-forming region whose fragmentation properties have not been well investigated yet. We aim to use ALMA (Atacama Large Millimeter and Submillimeter Array) high angular resolution data to identify the fragments in W51 IRS2 and to study the fragmentation properties on a spatial scale of 0.04" (200AU). We used ALMA data of W51 IRS2 from three projects, which give an angular resolution of 0.028" (144AU) at millimeter wavelengths. The continuum images reveal significant substructure in an east-west ridge, where both W51 North and W51d2 are embedded. A spectral index map has been generated from the 3 and 1.3mm high-resolution continuum images.We identified compact fragments by using uv-range constrained 1.3mm continuum data. A Mean Surface Density of Companions (MSDC) analysis has been performed to study the separations between fragments. A total number of 33 continuum sources are identified and 29 out of them are defined as fragments in the surveyed region.The MSDC analysis reveals two breaks corresponding to spatial sales of 1845AU and 7346AU, indicative of a two-level clustering phenomenon, along with a linear regime below 1845AU, mostly associated with W51 North, whose slope is consistent with the slope for the clustering regime of other cluster-like regions in the Galaxy. The typical masses and separations of the fragments as well as the relation between density and number of fragments can be explained through a thermal Jeans process operating at high temperatures of 200-400K, consistent with previous measurements of the temperature in the region, and produced by the nearby massive stars. Therefore, although W51 IRS2 seems to be undergoing a thermally inhibited fragmentation phase, this does not seem to prevent the formation of a protocluster associated with W51 North.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A96
- Title:
- Detection of the propargyl radical at lambda 3mm
- Short Name:
- J/A+A/657/A96
- Date:
- 21 Mar 2022 09:30:15
- Publisher:
- CDS
- Description:
- We report the detection of the propargyl radical (CH_2_CCH) in the cold dark cloud TMC-1 in the lambda 3mm wavelength band. We recently discovered this species in space toward the same source at a wavelength of lambda 8mm. In those observations, various hyperfine components of the 202-101 rotational transition, at 37.5GHz, were detected using the Yebes 40m telescope. Here, we used the IRAM 30m telescope to detect ten hyperfine components of the 505-404 rotational transition, lying at 93.6GHz. The observed frequencies differ by 0.2MHz with respect to the predictions from available laboratory data. This difference is significant for a radioastronomical search for CH_2_CCH in interstellar sources with narrow lines. We thus included the measured frequencies in a new spectroscopic analysis to provide accurate frequency predictions for the interstellar search for propargyl at mm wavelengths. Moreover, we recommend that future searches for CH_2_CCH in cold interstellar clouds are carried out at lambda 3mm, rather than at lambda 8 mm. The 505-404 transition is about five times more intense than the 202-101 transition in TMC-1, which implies that detecting the former requires about seven times less telescope time than detecting the latter. We constrain the rotational temperature of CH_2_CCH in TMC-1 to 9.9+/-1.5K, which indicates that the rotational levels of this species are thermalized at the gas kinetic temperature. The revised value of the column density of CH_2_CCH (including ortho and para species) is (1.0+/-0.2)x10^14^cm^-2^, and thus the CH_2_CCH/CH_3_CCH abundance ratio is revised from slightly below one to nearly one. This study opens the door for future detections of CH_2_CCH in other cold interstellar clouds, making possible to further investigate the role of this very abundant hydrocarbon radical in the synthesis of large organic molecules such as aromatic rings.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/79
- Title:
- Chandra obs. of SDSS AGN pairs at z_med_~0.1
- Short Name:
- J/ApJ/900/79
- Date:
- 21 Mar 2022 09:29:38
- Publisher:
- CDS
- Description:
- We present a Chandra archival study of optically selected active galactic nucleus (AGN) pairs at a median redshift z~0.1. Out of 1286 AGN pairs (with projected separations rp<100kpc and velocity offsets {Delta}v<600km/s) optically identified from the Sloan Digital Sky Survey Seventh Data Release, we find 67 systems with archival Chandra observations, which represents the largest sample of optically selected AGN pairs studied in the X-ray. Among the 67 AGN pairs, 21 systems have both nuclei detected in the X-ray, 36 have one nucleus detected in the X-ray, and 10 have no X-ray detection. The X-ray detection rate, 78/134=58% (+/-7% 1{sigma} Poisson errors), is significantly higher than that (23/134=17%+/-4%) of a comparison sample of star-forming galaxy pairs, lending support to the optical AGN classification. In the conservative case where X-ray contamination from star formation is removed, the X-ray detection rate becomes 27%+/-4%, consistent with predictions from the latest galaxy merger simulations. The 2-10keV X-ray luminosity L2-10keV increases with decreasing projected separation in AGN pairs for rp>~15kpc, suggesting an enhancement of black hole accretion even in early-stage mergers. On the other hand, L2-10keV appears to decrease with decreasing projected separation at rp<~15kpc, which is contradictory to predictions from merger simulations. The apparent decrease in L2-10 keV of AGN pairs at rp<~15kpc may be caused by (i) enhanced absorbing columns from merger-induced gas inflows, (ii) feedback effects from early-stage mergers, and/or (iii) small number statistics. Future X-ray studies with larger samples are needed to put our results on firmer statistical ground.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/55
- Title:
- The SPT-SZ catalog at 95, 150, and 220GHz
- Short Name:
- J/ApJ/900/55
- Date:
- 21 Mar 2022 09:29:14
- Publisher:
- CDS
- Description:
- We present a catalog of emissive point sources detected in the SPT-SZ survey, a contiguous 2530 square degree area surveyed with the South Pole Telescope (SPT) from 2008-2011 in three bands centered at 95, 150, and 220GHz. The catalog contains 4845 sources measured at a significance of 4.5{sigma} or greater in at least one band, corresponding to detections above approximately 9.8, 5.8, and 20.4mJy in 95, 150, and 220GHz, respectively. The spectral behavior in the SPT bands is used for source classification into two populations based on the underlying physical mechanisms of compact, emissive sources that are bright at millimeter wavelengths: synchrotron radiation from active galactic nuclei and thermal emission from dust. The latter population includes a component of high-redshift sources often referred to as submillimeter galaxies (SMGs). In the relatively bright flux ranges probed by the survey, these sources are expected to be magnified by strong gravitational lensing. The survey also contains sources consistent with protoclusters, groups of dusty galaxies at high redshift undergoing collapse. We cross-match the SPT-SZ catalog with external catalogs at radio, infrared, and X-ray wavelengths and identify available redshift information. The catalog splits into 3980 synchrotron-dominated and 865 dust-dominated sources, and we determine a list of 506 SMGs. Ten sources in the catalog are identified as stars. We calculate number counts for the full catalog, and synchrotron and dusty components, using a bootstrap method and compare our measured counts with models. This paper represents the third and final catalog of point sources in the SPT-SZ survey.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A70
- Title:
- Linking high- and low-mass star formation
- Short Name:
- J/A+A/657/A70
- Date:
- 21 Mar 2022 09:28:51
- Publisher:
- CDS
- Description:
- Astronomers have yet to establish whether high-mass protostars form from high-mass prestellar cores, similar to their lower-mass counterparts, or from lower-mass fragments at the heart of a pre-protostellar cluster undergoing large-scale collapse. Part of the uncertainty is due to a shortage of envelope structure data on protostars of a few tens of solar masses, where we expect to see a transition from intermediate-mass star formation to the high-mass process. We sought to derive the masses, luminosities, and envelope density profiles for eight sources in Cygnus-X, whose mass estimates in the literature placed them in the sampling gap. Combining these sources with similarly evolved sources in the literature enabled us to perform a meta-analysis of protostellar envelope parameters over six decades in source luminosity. We performed spectral energy distribution (SED) fitting on archival broadband photometric continuum data from 1.2 to 850 microns, to derive bolometric luminosities for our eight sources plus initial mass and radius estimates for modelling density and temperature profiles with the radiative transfer package Transphere. The envelope masses, densities at 1000AU, outer envelope radii, and density power law indices as functions of bolometric luminosity all follow established trends in the literature spanning six decades in luminosity. Most of our sources occupy an intermediate to moderately high range of masses and luminosities, which helps more firmly establish the continuity between low- and high-mass star formation mechanisms. Our density power law indices are consistent with observed values in literature, which show no discernible trends with luminosity. Finally, we show that the trends in all of the envelope parameters for high-mass protostars are statistically indistinguishable from trends in the same variables for low- and intermediate-mass protostars.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/47
- Title:
- UV to NIR spectra of the QSO 2MASS J15165323+1900482
- Short Name:
- J/ApJ/900/47
- Date:
- 21 Mar 2022 09:27:00
- Publisher:
- CDS
- Description:
- We present detailed studies of the partially obscured quasar 2MASSJ151653.23+190048.2 with continuous broadband spectrophotometry from near-infrared (NIR) through optical to ultraviolet (UV). The NIR and optical spectra show strong broad emission lines, while the UV spectrum is dominated by a set of rich intermediate-width emission lines (IELs). These IELs, unshifted with respect to the quasar systemic velocity measured by narrow emission lines, share a common profile of about 1900km/s in FWHM, in contrast to the Balmer and Paschen broad emission lines of FWHM ~6300km/s observed in the optical and NIR. The intermediate width of these lines indicates that the emitting gas may come from the dusty torus region. However, the observed peculiar IEL intensity ratios, such as NV{lambda}1240/Ly{alpha}, indicate that the emitting gas has a very high density, up to ~10^13^cm^-3^. Such a high density is unusual for gas around the dusty torus region, except that we consider mechanisms such as shocks that can produce local ultradense gas. We speculate that these emission lines could originate from the shock region, possibly induced by the quasar outflow colliding with the inner wall of the dusty torus. If true, this may give us an opportunity to peep at the quasar outflows at the scale of the dusty torus that have so far been elusive due to the limited resolving powers of existing facilities.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/42
- Title:
- CARMENES obs. of the binary system LB-1
- Short Name:
- J/ApJ/900/42
- Date:
- 21 Mar 2022 09:26:37
- Publisher:
- CDS
- Description:
- The mass, origin, and evolutionary stage of the binary system LB-1 have been intensely debated, following the claim that it hosts an ~70M_{sun}_ black hole, in stark contrast with the expectations for Galactic remnants. We conducted a high-resolution, phase-resolved spectroscopic study of its Paschen lines, using the Calar Alto 3.5m telescope. We find that Pa{beta} and Pa{gamma} (after subtraction of the stellar absorption component) are well fitted with a standard double-peaked disk profile. We measured the velocity shifts of the red and blue peaks at 28 orbital phases: the line center has an orbital motion in perfect antiphase with the secondary, and the radial velocity amplitude ranges from 8 to 13km/s, for different methods of profile modeling. We interpret this curve as proof that the disk traces the orbital motion of the primary, ruling out the circumbinary disk and the hierarchical triple scenarios. The phase-averaged peak-to-peak half-separation (a proxy for the projected rotational velocity of the outer part of the disk) is ~70km/s, larger than the orbital velocity of the secondary and inconsistent with a circumbinary disk. From those results, we infer a primary mass 4-8 times higher than the secondary mass. Moreover, we show that the intensity ratio of the blue and red peaks has a sinusoidal behavior in phase with the secondary, which we attribute to external irradiation of the outer part of the disk. Finally, we discuss our findings in the context of competing scenarios proposed for LB-1. Further astrometric Gaia data will test between alternative solutions.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A55
- Title:
- C3 by collision with H2
- Short Name:
- J/A+A/657/A55
- Date:
- 21 Mar 2022 09:24:59
- Publisher:
- CDS
- Description:
- An accurate analysis of the physical-chemical conditions in the regions of the interstellar medium in which C_3_ is observed requires knowing the collisional rate coefficients of this molecule with He, H_2_, electrons, and H. The main goals of this study are to present the first potential energy surface for the C_3_ +H_2_ complex, to study the dynamics of the system, and to report a set of rate coefficients at low temperature for the lower rotational states of C_3_ with para- and ortho-H_2_. Methods. A large grid of ab initio energies was computed at the explicitly correlated coupled-cluster with single-, double-, and perturbative triple-excitation level of theory, together with the augmented correlation-consistent quadruple zeta basis set (CCSD(T)-F12a/aug-cc-pVQZ). This grid of energies was fit to an analytical function. The potential energy surface was employed in close- coupling calculations at low collisional energies. We present a high-level four-dimensional potential energy surface (PES) for studying the collision of C_3_ with H_2_ . The global minimum of the surface is found in the linear HH-CCC configuration. Rotational deexcitation state-to-state cross sections of C_3_ by collision with para- and ortho-H_2_ are computed. Furthermore, a reduced two-dimensional surface is developed by averaging the surface over the orientation of H_2_. The cross sections for the collision with para-H_2_ using this approximation and those from the four-dimensional PES agree excellently. Finally, a set of rotational rate coefficients for the collision of C_3_ with para- and ortho-H_2_ at low temperatures are reported.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/L38
- Title:
- VLT/SPHERE Y-band images of MWC 758 at two epochs
- Short Name:
- J/ApJ/898/L38
- Date:
- 21 Mar 2022 09:24:26
- Publisher:
- CDS
- Description:
- More than a dozen young stars host spiral arms in their surrounding protoplanetary disks. The excitation mechanisms of such arms are under debate. The two leading hypotheses-companion-disk interaction and gravitational instability (GI)-predict distinct motion for spirals. By imaging the MWC 758 spiral arm system at two epochs spanning ~5yr using the SPHERE instrument on the Very Large Telescope (VLT), we test the two hypotheses for the first time. We find that the pattern speeds of the spirals are not consistent with the GI origin. Our measurements further evince the existence of a faint "missing planet" driving the disk arms. The average spiral pattern speed is 0.22+/-0.03/yr, pointing to a driver at 172_-14_^+18^ au around a 1.9M_{sun}_ central star if it is on a circular orbit. In addition, we witness time-varying shadowing effects on a global scale that are likely originating from an inner disk.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A31
- Title:
- Solar-like oscillations in Kepler DR25 SC data
- Short Name:
- J/A+A/657/A31
- Date:
- 21 Mar 2022 09:22:47
- Publisher:
- CDS
- Description:
- During the survey phase of the Kepler mission, several thousand stars were observed in short cadence, allowing for the detection of solar-like oscillations in more than 500 main-sequence and subgiant stars. These detections showed the power of asteroseismology in determining fundamental stellar parameters. However, the Kepler Science Office discovered an issue in the calibration that affected half of the store of short-cadence data, leading to a new data release (DR25) with corrections on the light curves. In this work, we re-analyzed the one-month time series of the Kepler survey phase to search for solar-like oscillations that might have been missed when using the previous data release. We studied the seismic parameters of 99 stars, among which there are 46 targets with new reported solar-like oscillations, increasing, by around 8%, the known sample of solar-like stars with an asteroseismic analysis of the short-cadence data from this mission. The majority of these stars have mid- to high-resolution spectroscopy publicly available with the LAMOST and APOGEE surveys, respectively, as well as precise Gaia parallaxes. We computed the masses and radii using seismic scaling relations and we find that this new sample features massive stars (above 1.2M_{sun}_ and up to 2M_{sun}_) and subgiants. We determined the granulation parameters and amplitude of the modes, which agree with the scaling relations derived for dwarfs and subgiants. The stars studied here are slightly fainter than the previously known sample of main-sequence and subgiants with asteroseismic detections. We also studied the surface rotation and magnetic activity levels of those stars. Our sample of 99 stars has similar levels of activity compared to the previously known sample and is in the same range as the Sun between the minimum and maximum of its activity cycle. We find that for seven stars, a possible blend could be the reason for the non-detection with the early data release. Finally, we compared the radii obtained from the scaling relations with the Gaia ones and we find that the Gaia radii are overestimated by 4.4%, on average, compared to the seismic radii, with a scatter of 12.3% and a decreasing trend according to the evolutionary stage. In addition, for homogeneity purposes, we re-analyzed the DR25 of the main-sequence and subgiant stars with solar-like oscillations that were previously detected and, as a result, we provide the global seismic parameters for a total of 525 stars.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A24
- Title:
- HCCCHCN laboratory observations
- Short Name:
- J/A+A/657/A24
- Date:
- 21 Mar 2022 09:22:16
- Publisher:
- CDS
- Description:
- The reaction between carbon atoms and vinyl cyanide, CH_2_CHCN, is a possible formation route for interstellar 3-cyano propargyl radical, CH_2_C_3_N. 1-Cyano propargyl radical (HC_3_HCN), an isomer of CH_2_C_3_N, is predicted to be produced in the same reaction at least twice more efficiently than CH_2_C_3_N. Hence, HC_3_HCN is a plausible candidate to be observed in space as well. We aim to generate HC_3_HCN radical in the gas phase in order to investigate its rotational spectrum. The derived spectroscopic parameters for this species will be use to obtain reliable frequency predictions to support its detection in the space. Rotational spectrum of HC_3_HCN radical was produce by electric discharges and characterized using a Balle-Flygare narrowband type Fourier-transform microwave (FTMW) spectrometer operating in the frequency region of 4-40GHz. The spectral analysis was supported by high-level ab initio calculations. A total of 193 hyperfine components originated from twelve rotational transitions, a- and b-type, were measured for HC_3_HCN radical. The analysis allowed us to accurately determine twenty-two molecular constants, including rotational and centrifugal distortion constants as well as the fine and hyperfine constants. Transition frequency predictions were used to search for HC_3_HCN radical in TMC-1 using the QUIJOTE survey between 30.1-50.4GHz. We can not confirm the presence of HC_3_HCN in TMC-1 and obtain an upper limit to the column density of HC_3_HCN in TMC-1 of 6.0*10^11^cm^-2^.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A17
- Title:
- Gaia 19bld spectroscopic follow-up
- Short Name:
- J/A+A/657/A17
- Date:
- 21 Mar 2022 09:21:49
- Publisher:
- CDS
- Description:
- As the event displayed an increased brightness, spectroscopic follow-up observations were immediately scheduled. Low-resolution spectra (R~500) were obtained using the FLOYDS spectrograph, which is mounted on the Las Cumbres Observatory (LCO) 2-m telescope at Siding Spring Observatory In addition,we used the X-shooter instrument mounted on the ESO Very Large Telescope (VLT) which is a multi-wavelength, medium-resolution spectrograph consisted of three spectroscopic arms allowing for simultaneous observations at three wavelength ranges: UVB (300-559.5nm), VIS (559.5-1024nm), and NIR (1024-2480nm). Spectra used in this publication.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A9
- Title:
- Virgo Filaments. I. CO and HI data
- Short Name:
- J/A+A/657/A9
- Date:
- 21 Mar 2022 09:21:25
- Publisher:
- CDS
- Description:
- It is now well established that galaxies have different morphology, gas content and star formation rate in dense environments like galaxy clusters. The impact of environmental density extends to several virial radii, and galaxies appear to be pre-processed in filaments and groups, before falling into the cluster. Our goal is to quantify this pre-processing, in terms of gas content, and star formation rate, as a function of density in cosmic filaments. We have observed the two first CO transitions in 163 galaxies with the IRAM-30m telescope, and added 82 more measurements from the literature, for a sample of 245 galaxies in the filaments around Virgo cluster. We gathered HI-21cm measurements from the literature, and observed 69 galaxies with the Nancay telescope, to complete our sample. We compare our filament galaxies with comparable samples from the Virgo cluster and with the isolated galaxies of the AMIGA sample. We find a clear progression from field galaxies to filament and cluster ones for decreasing star formation rate, increasing fraction of galaxies in the quenching phase, increasing proportion of early-type galaxies and decreasing gas content. Galaxies in the quenching phase, defined as having star formation rate below one third of the main sequence rate, are only between 0-20% in the isolated sample, according to local galaxy density, while they are 20-60% in the filaments and 30-80% in the Virgo cluster. Processes that lead to star formation quenching are already at play in filaments. They depend mostly on the local galaxy density, while the distance to the filament spine is a secondary parameter. While the HI to stellar mass ratio decreases with local density by an order of magnitude in the filaments, and two orders of magnitude in the Virgo cluster with respect to the field, the decrease is much less for the H2 to stellar mass ratio. As the environmental density increases, the gas depletion time decreases, since the gas content decreases faster than the star formation rate. This suggests that gas depletion significantly precedes star formation quenching.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A2
- Title:
- MACS J0717.5+3745 polarization int. maps
- Short Name:
- J/A+A/657/A2
- Date:
- 21 Mar 2022 09:20:37
- Publisher:
- CDS
- Description:
- We present wideband (1-6.5 GHz) polarimetric observations, obtained with the Karl G. Jansky Very Large Array (VLA), of the merging galaxy cluster MACS J0717.5+3745, which hosts one of the most complex known radio relic and halo systems. We use both Rotation Measure Synthesis and QU-fitting, and find a reasonable agreement of the results obtained with these methods, in particular, when the Faraday distribution is simple and the depolarization is mild. The relic is highly polarized over its entire length (850kpc), reaching a fractional polarization >30% in some regions. We also observe a strong wavelength-dependent depolarization for some regions of the relic. The northern part of the relic shows a complex Faraday distribution suggesting that this region is located in or behind the intracluster medium (ICM). Conversely, the southern part of the relic shows a Rotation Measure very close to the Galactic foreground, with a rather low Faraday dispersion, indicating very little magnetoionic material intervening the line-of-sight. From spatially resolved polarization analysis, we find that the scatter of Faraday depths correlates with the depolarization, indicating that the tangled magnetic field in the ICM causes the depolarization. We conclude that the ICM magnetic field could be highly turbulent. At the position of a well known narrow-angle-tailed galaxy (NAT), we find evidence of two components clearly separated in Faraday space. The high Faraday dispersion component seems to be associated with the NAT, suggesting the NAT is embedded in the ICM while the southern part of the relic lies in front of it. If true, this implies that the relic and this radio galaxy are not necessarily physically connected and thus, the relic may be not powered by the shock re-acceleration of fossil electrons from the NAT. The magnetic field orientation follows the relic structure indicating a well-ordered magnetic field. We also detect polarized emission in the halo region; however the absence of significant Faraday rotation and a low value of Faraday dispersion suggests the polarized emission, previously considered as the part of the halo, has a shock(s) origin.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A1
- Title:
- Maggie filament datacubes
- Short Name:
- J/A+A/657/A1
- Date:
- 21 Mar 2022 09:19:29
- Publisher:
- CDS
- Description:
- The atomic phase of the interstellar medium plays a key role in the formation process of molecular clouds. Due to the line-of-sight confusion in the Galactic plane that is associated with its ubiquity, atomic hydrogen emission has been challenging to study. We investigate the physical properties of the "Maggie" filament, a large-scale filament identified in HI emission at line-of-sight velocities, v_LSR_~-54km/s. Employing the high-angular resolution data from The HI/OH Recombination line survey of the inner Milky Way (THOR), we have been able to study HI emission features at negative v_LSR_ velocities without any line-of-sight confusion due to the kinematic distance ambiguity in the first Galactic quadrant. In order to investigate the kinematic structure, we decomposed the emission spectra using the automated Gaussian fitting algorithm GaussPy+. We identify one of the largest, coherent, mostly atomic HI filaments in the Milky Way. The giant atomic filament Maggie, with a total length of 1.2+/-0.1kpc, is not detected in most other tracers, and it does not show signs of active star formation. At a kinematic distance of 17kpc, Maggie is situated below (by ~500pc), but parallel to, the Galactic HI disk and is trailing the predicted location of the Outer Arm by 5-10km/s in longitude-velocity space. The centroid velocity exhibits a smooth gradient of less than 3(km/s)/(10pc) and a coherent structure to within +/-6km/s. The line widths of ~10km/s along the spine of the filament are dominated by nonthermal effects. After correcting for optical depth effects, the mass of Maggie's dense spine is estimated to be 7.2x10^5^ solar masses. The mean number density of the filament is ~4cm^-3^, which is best explained by the filament being a mix of cold and warm neutral gas. In contrast to molecular filaments, the turbulent Mach number and velocity structure function suggest that Maggie is driven by transonic to moderately supersonic velocities that are likely associated with the Galactic potential rather than being subject to the effects of self-gravity or stellar feedback. The probability density function of the column density displays a log-normal shape around a mean of 4.8x10^20^cm^-2^, thus reflecting the absence of dominating effects of gravitational contraction.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/166
- Title:
- UV to NIR obs. of SN 2019ehk
- Short Name:
- J/ApJ/898/166
- Date:
- 21 Mar 2022 09:18:33
- Publisher:
- CDS
- Description:
- We present panchromatic observations and modeling of the Calcium-rich supernova (SN) 2019ehk in the star-forming galaxy M100 (d~16.2Mpc) starting 10hr after explosion and continuing for ~300days. SN 2019ehk shows a double-peaked optical light curve peaking at t=3 and 15days. The first peak is coincident with luminous, rapidly decaying Swift-XRT-discovered X-ray emission (L_x_~10^41^erg/s at 3days; Lx{propto}t^-3^), and a Shane/Kast spectral detection of narrow H{alpha} and HeII emission lines (v~500km/s) originating from pre-existent circumstellar material (CSM). We attribute this phenomenology to radiation from shock interaction with extended, dense material surrounding the progenitor star at r<10^15^cm and the resulting cooling emission. We calculate a total CSM mass of ~7x10^-3^M_{sun}_ (M_He_/M_H_~6) with particle density n~10^9^cm^-3^. Radio observations indicate a significantly lower density n<10^4^cm^-3^ at larger radii r>(0.1-1)x10^17^cm. The photometric and spectroscopic properties during the second light-curve peak are consistent with those of Ca-rich transients (rise-time of t_r_=13.4!+/-0.210days and a peak B-band magnitude of M_B_=-15.1+/-0.200mag). We find that SN 2019ehk synthesized (3.1+/-0.11)x10^-2^M_{sun}_ of ^56^Ni and ejected M_ej_=(0.72+/-0.040)M_{sun}_ total with a kinetic energy E_k_=(1.8+/-0.10)x10^50^erg. Finally, deep HST pre-explosion imaging at the SN site constrains the parameter space of viable stellar progenitors to massive stars in the lowest mass bin (~10M_{sun}_) in binaries that lost most of their He envelope or white dwarfs (WDs). The explosion and environment properties of SN 2019ehk further restrict the potential WD progenitor systems to low-mass hybrid HeCO WD+CO WD binaries.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A150
- Title:
- Gas and young stars in CMa OB1 assoc.
- Short Name:
- J/A+A/654/A150
- Date:
- 21 Mar 2022 09:18:01
- Publisher:
- CDS
- Description:
- The relationship between young stellar clusters and their respective parental molecular clouds remains an open issue. Recent inquiries consider the similarities between substructures of clouds and clusters and whether they are a coincidence or, rather, an indication of a physical relationship. To address these issues, we studied the CMa OB1/R1 region, which shows evidence of a complex star formation history. We obtained molecular cloud mapping with the IRAM-30 metre telescope to reveal the physical conditions of an unexplored side of the CMa region with the aim of comparing the morphology of the clouds to the distribution of young stellar objects (YSOs). We also studied the cloud kinematics in pursuit of gradients and jet signatures that could trace different star formation scenarios. The YSOs were selected on the basis of astrometric data from Gaia EDR3 that characterize the moving groups. The distance of 1099_-24_^+25^pc was obtained for the sample, based on the mean error-weighted parallax. Optical and near-infrared photometry was used to verify the evolutionary status and circumstellar characteristics of the YSOs. Among the selected candidates, we found 40 members associated with the cloud: 1 Class I, 11 Class II, and 28 Class III objects. Comparing the spatial distribution of the stellar population with the cores revealed by the ^13^CO map, we verified that peaks of emission coincide with the position of YSOs, confirming the association of these objects to their dense natal gas. Our observations support the large-scale scenario of the CMa shell-like structure formation as a relic of successive supernova events.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A160
- Title:
- Comet C/2020 F3 (NEOWISE) emission lines
- Short Name:
- J/A+A/656/A160
- Date:
- 21 Mar 2022 09:16:33
- Publisher:
- CDS
- Description:
- Comet C/2020 F3 (NEOWISE) is considered to be the brightest comet observed in the northern hemisphere since the passage of comet C/1995 O1 (Hale-Bopp) in 1997. Since the study of comets offers a unique opportunity to investigate the early stages of the formation and evolution of our Sun and the Solar System, we obtained high-resolution optical spectra (R={lambda}/{Delta}{lambda}=115000) of comet NEOWISE. The unique passage and its brightness yielded spectra with a large number of emission lines, providing information on the coma composition and the physical and chemical processes occurring in the nucleus. The spectra have been used to generate a catalog of emission lines to be used for future studies of comets since there are no catalogs in the literature with such a high spectral resolution. Two high-resolution spectra of comet NEOWISE were obtained, on 26 July 2020 (geocentric distance of 0.7au) and 5 August 2020 (geocentric distance of 0.89au), with the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) echelle spectrograph installed on the 360cm Telescopio Nazionale Galileo (TNG). The spectra cover the range between 383 and 693nm, and have been extracted using the HARPS-N Data Reduction Pipeline. To analyze the spectra and compile the high-resolution catalog, we collected several laboratory molecular line lists that cover the same wavelength range as that of our spectra. To validate the final identification, we compared our catalog with other atlases that resulted from the spectral analysis of other comets. We generate a high-spectral-resolution catalog of emission lines observed in comet NEOWISE, providing the identification for 4488 lines. We found cometary lines due to CN, CH, C_2_, C_3_, and NH_2_ and atomic lines due to NaI and [OI].
- ID:
- ivo://CDS.VizieR/J/A+A/656/A154
- Title:
- ClG 0217+70 radio images
- Short Name:
- J/A+A/656/A154
- Date:
- 21 Mar 2022 09:15:55
- Publisher:
- CDS
- Description:
- Megaparsec-scale radio sources in the form of halos and relics are often detected in dynamically disturbed galaxy clusters. Although they are associated with merger-induced turbulence and shocks, respectively, their formation is not fully understood. Aims. We aim to identify the mechanisms responsible for particle acceleration and magnetic field amplification in the halo and relics of the galaxy cluster ClG 0217+70. We observed ClG 0217+70 with LOFAR at 141MHz and with VLA at 1.5GHz, and we combined these observations with VLA 1.4GHz archival data to study the morphological and spectral properties of the diffuse sources.We added Chandra archival data to examine the thermal and non-thermal properties of the halo. Our LOFAR and VLA data confirm the presence of a giant radio halo in the cluster centre and multiple relics in the outskirts. The radio and X-ray emission from the halo are correlated, implying a tight relation between the thermal and non-thermal components. The diuse radio structure in the south-east, with a projected size of 3.5Mpc, is the most extended radio relic detected to date. The spectral index across the relic width steepens towards the cluster centre, suggesting electron ageing in the post-shock regions. The shock Mach numbers for the relics derived from the spectral index map range between 2.0 and 3.2. However, the integrated spectral indices lead to increasingly high Mach numbers for the relics farther from the cluster centre. This discrepancy could be because the relation between injection and integrated spectra does not hold for distant shocks, suggesting that the cooling time for the radioemitting electrons is longer than the crossing time of the shocks. The variations in the surface brightness of the relics and the low Mach numbers imply that the radio-emitting electrons are re-accelerated from fossil plasma that could originate in active galactic nuclei.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A146
- Title:
- HCN and CN emission in Serpens Main region
- Short Name:
- J/A+A/656/A146
- Date:
- 21 Mar 2022 09:00:12
- Publisher:
- CDS
- Description:
- Ultraviolet radiation (UV) influences the physics and chemistry of star-forming regions, but its properties and significance in the immediate surroundings of low-mass protostars are still poorly understood. We aim to extend the use of the CN/HCN ratio, already established for high-mass protostars, to the low-mass regime to trace and characterize the UV field around low-mass protostars on ~0.6x0.6pc scales. The spatial distribution of HCN and CS are well-correlated with CO 6-5 emission that traces outflows. The CN emission is extended from the central protostars to their immediate surroundings also tracing outflows, likely as a product of HCN photodissociation. The ratio of CN to HCN total column densities ranges from ~1 to 12 corresponding to G_0_~10^1^-10^3^ for gas densities and temperatures typical for outflows of low-mass protostars. UV radiation associated with protostars and their outflows is indirectly identified in a significant part of the Serpens Main low-mass star-forming region. Its strength is consistent with the values obtained from the OH and H_2_O ratios observed with Herschel and compared with models of UV-illuminated shocks. From a chemical viewpoint, the CN to HCN ratio is an excellent tracer of UV fields around low- and intermediate-mass star-forming regions.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/150
- Title:
- High-res. MIKE obs. of metal-poor stars
- Short Name:
- J/ApJ/898/150
- Date:
- 21 Mar 2022 08:50:22
- Publisher:
- CDS
- Description:
- Extensive progress has recently been made in our understanding of heavy-element production via the r-process in the universe, specifically with the first observed neutron star binary merger (NSBM) event associated with the gravitational-wave signal detected by LIGO, GW170817. The chemical abundance patterns of metal-poor r-process-enhanced stars provide key evidence for the dominant site(s) of the r-process and whether NSBMs are sufficiently frequent or prolific r-process sources to be responsible for the majority of r-process material in the universe. We present atmospheric stellar parameters (using a nonlocal thermodynamic equilibrium analysis) and abundances from a detailed analysis of 141 metal-poor stars carried out as part of the R-Process Alliance (RPA) effort. We obtained high-resolution "snapshot" spectroscopy of the stars using the MIKE spectrograph on the 6.5m Magellan Clay telescope at Las Campanas Observatory in Chile. We find 10 new highly enhanced r-II (with [Eu/Fe]>+1.0), 62 new moderately enhanced r-I (+0.3<[Eu/Fe]<~+1.0), and 17 new limited-r ([Eu/Fe]<+0.3) stars. Among those, we find 17 new carbon-enhanced metal-poor (CEMP) stars, of which five are CEMP-no. We also identify one new s-process-enhanced ([Ba/Eu]>+0.5) and five new r/s (0.0<[Ba/Eu]<+0.5) stars. In the process, we discover a new ultra-metal-poor (UMP) star at [Fe/H]=-4.02. One of the r-II stars shows a deficit in {alpha} and Fe-peak elements, typical of dwarf galaxy stars. Our search for r-process-enhanced stars by RPA efforts has already roughly doubled the known r-process sample.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/102
- Title:
- Rotation velocity & dynamical mass of gal. from HI sp.
- Short Name:
- J/ApJ/898/102
- Date:
- 21 Mar 2022 08:49:45
- Publisher:
- CDS
- Description:
- The integrated 21cm HI emission profile of a galaxy encodes valuable information on the kinematics, spatial distribution, and dynamical state of its cold interstellar medium. The line width, in particular, reflects the rotation velocity of the galaxy, which, in combination with a size scale, can be used to constrain the dynamical mass of the system. We introduce a new method based on the concept of the curve of growth to derive a set of robust parameters to characterize the line width, asymmetry, and concentration of the integrated HI spectra. We use mock spectra to evaluate the performance of our method, to estimate realistic systematic uncertainties for the proposed parameters, and to correct the line widths for the effects of instrumental resolution and turbulence broadening. Using a large sample of nearby galaxies with available spatially resolved kinematics, we demonstrate that the newly defined line widths can predict the rotational velocities of galaxies to within an accuracy of <~30km/s. We use the calibrated line widths, in conjunction with the empirical relation between the size and mass of HI disks, to formulate a prescription for estimating the dynamical mass within the HI-emitting region of gas-rich galaxies. Our formalism yields dynamical masses accurate to ~0.3dex based solely on quantities that can be derived efficiently and robustly from current and future extragalactic HI surveys. We further extend the dynamical mass calibration to the scale of the dark matter halo.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/85
- Title:
- CII emission-line stars in LMC with MagE spectra
- Short Name:
- J/ApJ/898/85
- Date:
- 21 Mar 2022 08:48:14
- Publisher:
- CDS
- Description:
- We present a narrowband imaging survey of the Large Magellanic Cloud (LMC), designed to isolate the CII{lambda}{lambda}7231,7236 emission lines in objects as faint as m_{lambda}7400_~18. The work is motivated by the recent serendipitous discovery in the LMC of the first confirmed extragalactic [WC11] star, whose spectrum is dominated by CII emission, and the realization that the number of such objects is currently largely unconstrained. The survey, which imaged ~50deg^2^ using on-band and off-band filters, will significantly increase the total census of these rare stars. In addition, each new LMC [WC] star has a known luminosity, a quantity quite uncertain in the Galactic sample. Multiple known CII emitters were easily recovered, validating the survey design. We find 38 new CII emission candidates; spectroscopy of the complete sample will be needed to ascertain their nature. In a preliminary spectroscopic reconnaissance, we observed three candidates, finding CII emission in each. One is a new [WC11]. Another shows both the narrow CII emission lines characteristic of a [WC11], but also broad emission of CIV, OV, and HeII characteristic of a much hotter [WC4] star; we speculate that this is a binary [WC]. The third object shows weak CII emission, but the spectrum is dominated by a dense thicket of strong absorption lines, including numerous OII transitions. We conclude it is likely an unusual hot, hydrogen-poor post-AGB star, possibly in transition from [WC] to white dwarf. Even lacking a complete spectroscopic program, we can infer that late [WC] stars do not dominate the central stars of LMC planetary nebulae, and that the detected CII emitters are largely of an old population.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/76
- Title:
- Rot. velocities of APOGEE stars in Kepler field
- Short Name:
- J/ApJ/898/76
- Date:
- 21 Mar 2022 08:47:46
- Publisher:
- CDS
- Description:
- We use 5337 spectroscopic vsini measurements of Kepler dwarfs and subgiants from the APOGEE survey to study stellar rotation trends. We find a detection threshold of 10km/s, which allows us to explore the spindown of intermediate-mass stars leaving the main sequence, merger products, young stars, and tidally synchronized binaries. We see a clear distinction between blue stragglers and the field turnoff in {alpha}-rich stars, with a sharp rapid rotation cutoff for blue stragglers consistent with the Kraft break. We also find rapid rotation and radial velocity variability in a sample of red straggler stars, considerably cooler than the giant branch, lending credence to the hypothesis that these are active, tidally synchronized binaries. We see clear evidence for a transition between rapid and slow rotation on the subgiant branch in the domain predicted by modern angular momentum evolution models. We find substantial agreement between the spectroscopic and photometric properties of KIC targets added by Huber+ (2014, J/ApJS/211/2) based on Two Micron All Sky Survey photometry. For the unevolved lower main sequence, we see the same concentration toward rapid rotation in photometric binaries as that observed in rotation period data, but at an enhanced rate. We attribute this difference to unresolved near-equal-luminosity spectroscopic binaries with velocity displacements on the order of the APOGEE resolution. Among cool unevolved stars we find an excess rapid rotator fraction of 4% caused by pipeline issues with photometric binaries.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/83
- Title:
- BH masses and bulge+disk UV-3.6um color relations
- Short Name:
- J/ApJ/898/83
- Date:
- 21 Mar 2022 08:47:28
- Publisher:
- CDS
- Description:
- The tight correlations between supermassive black hole (SMBH) mass (MBH) and the properties of the host galaxy have useful implications for our understanding of the growth of SMBHs and of the evolution of galaxies. Here, we present newly observed correlations between MBH and the host galaxy total UV-[3.6] color (C_UV,tot_, Pearson's r=0.6-0.7) for a sample of 67 galaxies (20 early-type galaxies and 47 late-type galaxies) with directly measured MBH in the Galaxy Evolution Explorer/S4G survey. The colors are carefully measured in a homogeneous manner using the far-UV, near-UV, and 3.6{mu}m magnitudes of the galaxies and their multicomponent structural decompositions in the literature. We find that more massive SMBHs are hosted by (early- and late-type) galaxies with redder colors, but the M_BH_-C_UV,tot_ relations for the two morphological types have slopes that differ at ~2{sigma} level. Early-type galaxies define a red sequence in the M_BH_-C_UV,tot_ diagrams, while late-type galaxies trace a blue sequence. Within the assumption that the specific star formation rate of a galaxy (sSFR) is well traced by L_UV_/L_3.6_, it follows that the SMBH masses for late-type galaxies exhibit a steeper dependence on sSFR than those for early-type galaxies. The M_BH_-C_UV,tot_ and M_BH_-L_3.6,tot_ relations for the sample galaxies reveal a comparable level of vertical scatter in the log MBH direction, approximately 5%-27% more than the vertical scatter of the M_BH_-{sigma} relation. Our M_BH_-C_UV,tot_ relations suggest different channels of SMBH growth for early- and late-type galaxies, consistent with their distinct formation and evolution scenarios. These new relations offer the prospect of estimating SMBH masses reliably using the galaxy color alone. Furthermore, we show that they are capable of estimating intermediate black hole masses in low-mass early- and late-type galaxies.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/77
- Title:
- NIR spectra of 2 extreme T-type subdwarfs
- Short Name:
- J/ApJ/898/77
- Date:
- 21 Mar 2022 08:47:02
- Publisher:
- CDS
- Description:
- We present the discoveries of WISEAJ041451.67-585456.7 and WISEAJ181006.18-101000.5, two low-temperature (1200-1400K), high proper motion T-type subdwarfs. Both objects were discovered via their high proper motion (>0.5yr^-1^); WISEA J181006.18-101000.5 as part of the NEOWISE proper motion survey and WISEA J041451.67-585456.7 as part of the citizen science project Backyard Worlds; Planet 9. We have confirmed both as brown dwarfs with follow-up near-infrared spectroscopy. Their spectra and near-infrared colors are unique among known brown dwarfs, with some colors consistent with L-type brown dwarfs and other colors resembling those of the latest-type T dwarfs. While no forward model consistently reproduces the features seen in their near-infrared spectra, the closest matches suggest very low metallicities ([Fe/H]<=-1), making these objects likely the first examples of extreme subdwarfs of the T spectral class (esdT). WISEAJ041451.67-585456.7 and WISEA J181006.18-101000.5 are found to be part of a small population of objects that occupy the "substellar transition zone", and have the lowest masses and effective temperatures of all objects in this group.
- ID:
- ivo://CDS.VizieR/J/A+A/655/A89
- Title:
- Mrk421 multi-instrument observations in 2017
- Short Name:
- J/A+A/655/A89
- Date:
- 21 Mar 2022 08:46:33
- Publisher:
- CDS
- Description:
- We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with a special focus on the multi-band flux correlations. The dataset has been collected through an extensive multi-wavelength campaign organised between 2016 December and 2017 June. The instruments involved are MAGIC, FACT, Fermi-LAT, Swift, GASP-WEBT, OVRO, Medicina, and Metsahovi. Additionally, four deep exposures (several hours long) with simultaneous MAGIC and NuSTAR observations allowed a precise measurement of the falling segments of the two spectral components. The very-high-energy (VHE; E>100GeV) gamma rays and X-rays are positively correlated at zero time lag, but the strength and characteristics of the correlation change substantially across the various energy bands probed. The VHE versus X-ray fluxes follow different patterns, partly due to substantial changes in the Compton dominance for a few days without a simultaneous increase in the X-ray flux (i.e. orphan gamma-ray activity). Studying the broadband spectral energy distribution (SED) during the days including NuSTAR observations, we show that these changes can be explained within a one-zone leptonic model with a blob that increases its size over time. The peak frequency of the synchrotron bump varies by two orders of magnitude throughout the campaign. Our multi-band correlation study also hints at an anti-correlation between UV-optical and X-ray at a significance higher than 3{sigma}. A VHE flare observed on MJD~57788 (2017 February 4) shows gamma-ray variability on multi-hour timescales, with a factor ten increase in the TeV flux but only a moderate increase in the keV flux. The related broadband SED is better described by a two-zone leptonic scenario rather than by a one-zone scenario. We find that the flare can be produced by the appearance of a compact second blob populated by high energetic electrons spanning a narrow range of Lorentz factors, from {gamma}'_min_=2x10^4^ to {gamma}'_max_=6x10^5^.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/46
- Title:
- NIR LCs of RRab stars from the VVV survey
- Short Name:
- J/ApJ/898/46
- Date:
- 21 Mar 2022 07:11:54
- Publisher:
- CDS
- Description:
- Aiming to extend the census of RR Lyrae stars to highly reddened low-latitude regions of the central Milky Way, we performed a deep near-IR variability search using data from the VISTA Variables in the Via Lactea (VVV) survey of the bulge, analyzing the photometric time series of over a hundred million point sources. In order to separate fundamental-mode RR Lyrae (RRab) stars from other periodically variable sources, we trained a deep bidirectional long short-term memory recurrent neural network (RNN) classifier using VVV survey data and catalogs of RRab stars discovered and classified by optical surveys. Our classifier attained a ~99% precision and recall for light curves with signal-to-noise ratio above 60, and is comparable to the best-performing classifiers trained on accurate optical data. Using our RNN classifier, we identified over 4300 hitherto unknown bona fide RRab stars toward the inner bulge. We provide their photometric catalog and VVV J,H,Ks photometric time series.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A99
- Title:
- Tomography with Magnification Bias
- Short Name:
- J/A+A/656/A99
- Date:
- 21 Mar 2022 07:10:35
- Publisher:
- CDS
- Description:
- High-z submillimetre galaxies can be used as a background sample for gravitational lensing studies thanks to their magnification bias. In particular, the magnification bias can be exploited in order to constrain the free parameters of a halo occupation distribution (HOD) model and some of the main cosmological parameters. A pseudo-tomographic analysis shows that the tomographic approach should improve the parameter estimation. In this work the magnification bias has been evaluated as cosmological tool in a tomographic set up. The cross-correlation function (CCF) data have been used to jointly constrain the astrophysical parameters M_min_, M_1_ and {alpha} in each one of the selected redshift bins, as well as the cosmological parameter {Omega}_M_, {sigma}_8_ and H_0_ for the lambda cold dark matter ({Lambda}CMD). Moreover, we explore the possible time evolution of the dark energy density introducing the {omaga}_0_ and {omage}_a_ parameters in the joint analysis ({omega}_0_CDM and {omega}_0_{omega}_a_CDM). The CCF was measured between a foreground spectroscopic sample of Galaxy And Mass Assembly galaxies and a background sample of Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) galaxies. The foreground sample was divided into four redshift bins (0.1-0.2, 0.2-0.3, 0.3-0.5, and 0.5-0.8) and the sample of H-ATLAS galaxies has photometric redshifts >1.2. The CCF was modelled using a halo model description that depends on HOD and cosmological parameters. Then a Markov chain Monte Carlo method was used to estimate the parameters for different cases. For the {Lambda}CDM model the analysis yields a maximum posterior value at 0.26 with [0.17, 0.41] 68% C.I. for {Omega}_M_ and at 0.87 with [0.75, 1] 68% C.I. for {sigma}_8_. With our current results H_0_ is not yet constrained. With a more general {omega}_0_CDM model, the constraints on {Omega}_M_ and {sigma}_8_ are similar, but we found a maximum posterior value for {omega}_0_ at -1 with [-1.56, -0.47] 68% C.I. In the {omega}_0_{omega}_a_CDM model, the results are -1.09 with [-1.72, -0.66] 68% C.I. for {omega}_0_ and -0.19 with [-1.88, 1.48] 68% C.I. for {omega}_a_. The results on Mmin show a trend towards higher values at higher redshift confirming recent findings. The tomographic analysis presented in this work improves the constraints in the {sigma}_8_-{Omega}_M_ plane with respect to previous findings exploiting the magnification bias and it confirms that magnification bias results do not show the degeneracy found with cosmic shear measurements. Moreover, related to dark energy, we found a trend of higher {omega}_0_ values for lower H_0_ values.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/21
- Title:
- Spitzer/IRAC obs. of HD113766 & HD172555 systems
- Short Name:
- J/ApJ/898/21
- Date:
- 21 Mar 2022 07:07:57
- Publisher:
- CDS
- Description:
- We present multiepoch infrared photometry and spectroscopy obtained with warm Spitzer, Subaru, and the Stratospheric Observatory for Infrared Astronomy to assess variability for the young (~20Myr) and dusty debris systems around HD 172555 and HD 113766A. No variations (within 0.5%) were found for the former at either 3.6 or 4.5{mu}m, while significant nonperiodic variations (peak to peak of ~10%-15% relative to the primary star) were detected for the latter. Relative to the Spitzer Infrared Spectrograph spectra taken in 2004, multiepoch mid-infrared spectra reveal no change in either the shape of the prominent 10{mu}m solid-state features or the overall flux levels (no more than 20%) for both systems, corroborating the fact that the population of submicron-size grains that produce the pronounced solid-state features is stable over a decadal timescale. We suggest that these submicron-size grains were initially generated in an optically thick clump of debris of millimeter-size vapor condensates resulting from a recent violent impact between large asteroidal or planetary bodies. Because of the shielding from the stellar photons provided by this clump, intense collisions led to an overproduction of fine grains that would otherwise be ejected from the system by radiation pressure. As the clump is sheared by its orbital motion and becomes optically thin, a population of very fine grains could remain in stable orbits until Poynting-Robertson drag slowly spirals them into the star. We further suggest that the 3-5{mu}m disk variation around HD 113766A is consistent with a clump/arc of such fine grains on a modestly eccentric orbit in its terrestrial zone.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/14
- Title:
- GRB spectral properties from Fermi and Swift
- Short Name:
- J/ApJ/898/14
- Date:
- 21 Mar 2022 07:04:24
- Publisher:
- CDS
- Description:
- We statistically examine the gamma-ray burst (GRB) photon indices obtained by the Fermi-GBM and Fermi-LAT observations and compare the LAT GRB photon indices to the GBM GRB photon indices. We apply the jitter radiation to explain the GRB spectral diversities in the high-energy bands. In our model, the jitter radiative spectral index is determined by the spectral index of the turbulence. We classify GRBs into three classes depending on the shape of the GRB high-energy spectrum when we compare the GBM and LAT detections: the GRB spectrum is concave (GRBs turn out to be softer and are labeled as S-GRBs), the GRB spectrum is convex (GRBs turn out to be harder and are labeled as H-GRBs), and the GRBs have no strong spectral changes (labeled as N-GRBs). A universal Kolmogorov index 7/3 in the turbulent cascade is consistent with the photon index of the N-GRBs. The S-GRB spectra can be explained by the turbulent cascade due to the kinetic magnetic reconnection with the spectral index range of the turbulence from 8/3 to 3.0. The H-GRB spectra originate from the inverse turbulent cascade with the spectral index range of the turbulence from 2.0 to 3.5 that occurred during the large lengthscale magnetic reconnection. Thus, the GRB radiative spectra are diversified because the turbulent cascade modifies the turbulent energy spectrum. More observational samples are expected in the future to further identify our suggestions.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A101
- Title:
- G305 Giant Molecular Cloud II. Clump properties
- Short Name:
- J/A+A/656/A101
- Date:
- 21 Mar 2022 07:03:46
- Publisher:
- CDS
- Description:
- G305 star-forming complex was observed in the 3-2 lines of 12 & 13CO to investigate the effect of feedback from the central OB stars on the complex. The region was decomposed into clumps using dendrogram analysis. A catalog of clump properties was created. The surface mass densities of the clumps were plotted as a function of the incident 8um flux. A mask of the region with 8um flux >100MJy/sr was created and clumps were categorized based on the extent of overlap with the mask into "mostly inside", "partly inside" & "outside". The surface mass density distribution of each of these populations were plotted. This was followed by comparing G305 clumps with the Galactic average taken from the ATLASGAL and CHIMPS clumps. Finally, the cumulative distribution functions (CDF) of the clump masses in G305 & their L/M ratios were compared to that of the Galactic sample. The surface mass densities of clumps showed a positive correlation with incident 8um flux. The data did not have sufficient velocity resolution to discern the effects of feedback on the linewidths of the clumps. The sub-sample of clumps named "mostly inside" had the highest surface mass densities followed by "partly -inside" and "outside" sub-samples. These differences between the three sub-samples were shown to be statistically significant using the KS test. The "mostly inside" sample also showed the highest level of fragmentation compared to the other two. These prove that clumps inside the G305 region are triggered. The G305 clump population is also statistically different from the Galactic average population rejecting redistribution as a likely consequence of feedback. The CDFs of clump masses and their L/M ratios are both flatter than the Galactic average, indicating that feedback in G305 has triggered star formation. The collect & collapse method is the dominant mechanism at play in G305.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/L43
- Title:
- Cepheids HST amplitudes in V- and H-band
- Short Name:
- J/ApJ/896/L43
- Date:
- 21 Mar 2022 07:02:57
- Publisher:
- CDS
- Description:
- The accuracy of the Hubble constant measured with extragalactic Cepheids depends on robust photometry and background estimation in the presence of stellar crowding. The conventional approach accounts for crowding by sampling backgrounds near Cepheids and assuming that they match those at their positions. We show a direct consequence of crowding by unresolved sources at Cepheid sites is a reduction in the fractional amplitudes of their light curves. We use a simple analytical expression to infer crowding directly from the light curve amplitudes of >200 Cepheids in three Type Ia supernovae hosts and NGC4258 as observed by Hubble Space Telescope-the first near-infrared amplitudes measured beyond the Magellanic Clouds. Where local crowding is minimal, we find near-infrared amplitudes match Milky Way Cepheids at the same periods. At greater stellar densities we find that the empirically measured amplitudes match the values predicted (with no free parameters) from crowding assessed in the conventional way from local regions, confirming their accuracy for estimating the background at the Cepheid locations. Extragalactic Cepheid amplitudes would need to be ~20% smaller than measured to indicate additional, unrecognized crowding as a primary source of the present discrepancy in H0. Rather, we find the amplitude data constrains a systematic mis-estimate of Cepheid backgrounds to be 0.029R+/-0.037mag, more than 5x smaller than the size of the present ~0.2mag tension in H0. We conclude that systematic errors in Cepheid backgrounds do not provide a plausible resolution to the Hubble tension.
- ID:
- ivo://CDS.VizieR/J/A+A/656/A60
- Title:
- NGC1808 ALMA datacubes
- Short Name:
- J/A+A/656/A60
- Date:
- 21 Mar 2022 07:01:58
- Publisher:
- CDS
- Description:
- We report on Atacama Large Millimeter Array (ALMA) observations of CO(3-2) emission in the Seyfert2/starburst galaxy NGC 1808, at a spatial resolution of 4pc. Our aim is to investigate the morphology and dynamics of the gas inside the central 0.5kpc and to probe the nuclear feeding and feedback phenomena. We discovered a nuclear spiral of radius 1"=45pc. Within it, we found a decoupled circumnuclear disk or molecular torus of a radius of 0.13"=6pc. The HCN(4-3) and HCO^+^(4-3) and CS(7-6) dense gas line tracers were simultaneously mapped and detected in the nuclear spiral and they present the same misalignment in the molecular torus. At the nucleus, the HCN/HCO^+^ and HCN/CS ratios indicate the presence of an active galactic nucleus (AGN). The molecular gas shows regular rotation, within a radius of 400pc, except for the misaligned disk inside the nuclear spiral arms. The computations of the torques exerted on the gas by the barred stellar potential reveal that the gas within a radius of 100pc is feeding the nucleus on a timescale of five rotations or on an average timescale of ~60Myr. Some non-circular motions are observed towards the center, corresponding to the nuclear spiral arms. We cannot rule out that small extra kinematic perturbations could be interpreted as a weak outflow attributed to AGN feedback. The molecular outflow detected at >=250pc in the NE direction is likely due to supernovae feedback and it is connected to the kpc-scale superwind.
- ID:
- ivo://CDS.VizieR/J/ApJ/896/L20
- Title:
- Swift BAT gamma-ray burst durations
- Short Name:
- J/ApJ/896/L20
- Date:
- 21 Mar 2022 07:00:25
- Publisher:
- CDS
- Description:
- The duration of a gamma-ray burst (GRB) is a key indicator of its physical origin, with long bursts perhaps associated with the collapse of massive stars and short bursts with mergers of neutron stars. However, there is substantial overlap in the properties of both short and long GRBs and neither duration nor any other parameter so far considered completely separates the two groups. Here we unambiguously classify every GRB using a machine-learning dimensionality reduction algorithm, t-distributed stochastic neighborhood embedding, providing a catalog separating all Swift GRBs into two groups. Although the classification takes place only using prompt emission light curves, every burst with an associated supernova is found in the longer group and bursts with kilonovae in the short, suggesting along with the duration distributions that these two groups are truly long and short GRBs. Two bursts with a clear absence of a supernova belong to the longer class, indicating that these might have been direct-collapse black holes, a proposed phenomenon that may occur in the deaths of more massive stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/903/L11
- Title:
- OGLE and KMTNet light curve of OGLE-2016-BLG-1928
- Short Name:
- J/ApJ/903/L11
- Date:
- 21 Mar 2022 06:18:03
- Publisher:
- CDS
- Description:
- Some low-mass planets are expected to be ejected from their parent planetary systems during early stages of planetary system formation. According to planet formation theories, such as the core accretion theory, typical masses of ejected planets should be between 0.3 and 1.0M{Earth}. Although in practice such objects do not emit any light, they may be detected using gravitational microlensing via their light-bending gravity. Microlensing events due to terrestrial-mass rogue planets are expected to have extremely small angular Einstein radii (<~1{mu}as) and extremely short timescales (<~0.1day). Here, we present the discovery of the shortest-timescale microlensing event, OGLE-2016-BLG-1928, identified to date (t_E_~0.0288day=41.5min. Thanks to the detection of finite-source effects in the light curve of the event, we were able to measure the angular Einstein radius of the lens {theta}_E_=0.842{+/-}0.064{mu}as, making the event the most extreme short-timescale microlens discovered to date. Depending on its unknown distance, the lens may be a Mars- to Earth-mass object, with the former possibility favored by the Gaia proper motion measurement of the source. The planet may be orbiting a star but we rule out the presence of stellar companions up to the projected distance of ~8.0au from the planet. Our discovery demonstrates that terrestrial-mass free-floating planets can be detected and characterized using microlensing.
- ID:
- ivo://CDS.VizieR/J/ApJ/903/151
- Title:
- MMT spectroscopic redshift catalog of the A521 field
- Short Name:
- J/ApJ/903/151
- Date:
- 21 Mar 2022 05:59:04
- Publisher:
- CDS
- Description:
- A521 has been a subject of extensive panchromatic studies from X-ray to radio. The cluster possesses a number of remarkable features, including a bright radio relic with a steep spectrum, more than three distinct galaxy groups forming a filament, and two disturbed X-ray peaks at odds with the distant position and tilted orientation of the radio relic. These lines of evidence indicate a complex merger. In this paper, we present a multiwavelength study of A521 based on Subaru optical, Hubble Space Telescope infrared, Chandra X-ray, Giant Metrewave Radio Telescope radio, and Multiple Mirror Telescope optical spectroscopic observations. Our weak-lensing (WL) analysis with improved systematics control reveals that A521 is mainly composed of three substructures aligned in the northwest to southeast orientation. These WL mass substructures are remarkably well-aligned with the cluster optical luminosity distribution constructed from our new enhanced cluster member catalog. These individual substructure masses are determined by simultaneously fitting three Navarro-Frenk-White profiles. We find that the total mass of A521 modeled by the superposition of the three halos is 13.0_-1.3_^+1.0^x10^14^M{odot}, a factor of 2 higher than the previous WL measurement. With these WL mass constraints combined with X-ray and radio features, we consider two merging scenarios, carry out the corresponding numerical simulations, and discuss the strengths and weaknesses of each case.
- ID:
- ivo://CDS.VizieR/J/AJ/162/117
- Title:
- Radial velocity for 19 RR Lyrae
- Short Name:
- J/AJ/162/117
- Date:
- 21 Mar 2022 00:54:18
- Publisher:
- CDS
- Description:
- We report 272 radial velocities for 19 RR-Lyrae variables. For most of the stars we have radial velocities for the complete pulsation cycle. These data are used to determine robust center-of-mass radial velocities that have been compared to values from the literature in a search for evidence of binary systems. Center-of-mass velocities were determined for each star using Fourier Series and template fits to the radial velocities. Our center-of-mass velocities have uncertainties from {+/-}0.16km/s to {+/-}2.5km/s, with a mean uncertainty of {+/-}0.92km/s. We combined our center-of-mass velocities with values from the literature to look for deviations from the mean center-of-mass velocity of each star. Fifteen RR-Lyrae show no evidence of binary motion (BK And, CI And, Z CVn, DM Cyg, BK Dra, RR Gem, XX Hya, SZ Leo, BX Leo, TT Lyn, CN Lyr, TU Per, U Tri, RV UMa, and AV Vir). In most cases this conclusion is reached due to the sporadic sampling of the center-of-mass velocities over time. Three RR Lyrae show suspicious variation in the center-of-mass velocities that may indicate binary motion but do not prove it (SS Leo, ST Leo, and AO Peg). TU UMa was observed by us near a predicted periastron passage (at 0.14 in orbital phase) but the absence of additional center-of-mass velocities near periastron makes the binary detection, based on radial velocities alone, uncertain. Two stars in our sample show H{gamma} emission in phases 0.9-1.0: SS Leo and TU UMa.
- ID:
- ivo://CDS.VizieR/J/AJ/162/125
- Title:
- Searching transiting planets around halo stars. I.
- Short Name:
- J/AJ/162/125
- Date:
- 21 Mar 2022 00:52:16
- Publisher:
- CDS
- Description:
- By measuring the elemental abundances of a star, we can gain insight into the composition of its initial gas cloud-the formation site of the star and its planets. Planet formation requires metals, the availability of which is determined by the elemental abundance. In the case where metals are extremely deficient, planet formation can be stifled. To investigate such a scenario requires a large sample of metal-poor stars and a search for planets therein. This paper focuses on the selection and validation of a halo star sample. We select ~17000 metal-poor halo stars based on their Galactic kinematics, and confirm their low metallicities ([Fe/H]<-0.5), using spectroscopy from the literature. Furthermore, we perform high-resolution spectroscopic observations using LBT/PEPSI and conduct detailed metallicity ([Fe/H]) analyses on a sample of 13 previously-known halo stars that also have hot kinematics. We can use the halo star sample presented here to measure the frequency of planets and to test planet formation in extremely metal-poor environments. The result of the planet search and its implications will be presented and discussed in a companion paper by Boley et al.
- ID:
- ivo://CDS.VizieR/J/AJ/162/13
- Title:
- Parameters estimation for 173 eclipsing binaries
- Short Name:
- J/AJ/162/13
- Date:
- 21 Mar 2022 00:50:18
- Publisher:
- CDS
- Description:
- High precision CCD observations of six totally eclipsing contact binaries were presented and analyzed. It is found that only one target is an A-type contact binary (V429Cam), while the others are W-type contact ones. By analyzing the times of light minima, we discovered that two of them exhibit secular period increase while three manifest long-term period decrease. For V1033Her, a cyclic variation superimposed on the long-term increase was discovered. By comparing the Gaia distances with those calculated by the absolute parameters of 173 contact binaries, we found that the Gaia distance can be applied to estimate the absolute parameters for most contact binaries. The absolute parameters of our six targets were estimated using their Gaia distances. The evolutionary status of contact binaries was studied, and we found that the A- and W-subtype contact binaries may have different formation channels. The relationship between the spectroscopic and photometric mass ratios for 101 contact binaries was presented. It was discovered that the photometric mass ratios are in good agreement with the spectroscopic ones for almost all of the totally eclipsing systems, which is corresponding to the results derived by Pribulla et al. and Terrell & Wilson.
- ID:
- ivo://CDS.VizieR/J/AJ/162/140
- Title:
- The SOS. VII. UBVI photometry of open cluster IC 1590
- Short Name:
- J/AJ/162/140
- Date:
- 21 Mar 2022 00:39:36
- Publisher:
- CDS
- Description:
- Young open clusters are ideal laboratories to understand the star formation process. We present deep UBVI and H{alpha} photometry for the young open cluster IC1590 in the center of the HII region NGC281. Early-type members are selected from UBV photometric diagrams, and low-mass pre-main-sequence (PMS) members are identified by using H{alpha} photometry. In addition, the published X-ray source list and Gaia astrometric data are also used to isolate probable members. A total of 408 stars are selected as members. The mean reddening obtained from early-type members is <E(B-V)>=0.40{+/-}0.06(s.d.). We confirm the abnormal extinction law for the intracluster medium. The distance modulus to the cluster determined from the zero-age main-sequence fitting method is 12.3{+/-}0.2mag (d=2.88{+/-}0.28kpc), which is consistent with the distance d=2.70_-0.20_^+0.24^kpc from the recent Gaia parallaxes. We also estimate the ages and masses of individual members by means of stellar evolutionary models. The mode of the age of PMS stars is about 0.8Myr. The initial mass function of IC1590 is derived. It appears to be a steeper shape ({Gamma}=-1.49{+/-}0.14) than that of the Salpeter/Kroupa initial mass function for the high-mass regime (m>1M{sun}). The signature of mass segregation is detected from the difference in the slopes of the initial mass functions for the inner (r<2.5') and outer regions of this cluster. We finally discuss the star formation history in NGC281.
- ID:
- ivo://CDS.VizieR/J/AJ/162/146
- Title:
- Kinematic and photometry of King 11 with Gaia EDR3
- Short Name:
- J/AJ/162/146
- Date:
- 21 Mar 2022 00:29:39
- Publisher:
- CDS
- Description:
- This paper presents an investigation of an old age open cluster King11 using Gaia's Early Data Release 3 data. Considering the stars with membership probability (P{mu})>90%, we identified 676 most probable cluster members within the cluster's limiting radius. The mean proper motion for King11 is determined as: {mu}x=-3.391{+/-}0.006 and {mu}y=-0.660{+/-}0.004mas/yr. The blue straggler stars of King11 show a centrally concentrated radial distribution. The values of limiting radius, age, and distance are determined as 18.51, 3.63{+/-}0.42Gyr, and 3.33{+/-}0.15kpc, respectively. The cluster's apex coordinates (A=267.84{+/-}1.01, D=-27.48{+/-}1.03) are determined using the apex diagram method and verified using the ({mu}U, {mu}T) diagram. We also obtained the orbit that the cluster follows in the Galaxy and estimated its tentative birthplace in the disk. The resulting spatial velocity of King 11 is 60.2{+/-}2.16km/s. A significant oscillation along the Z coordinate up to 0.556{+/-}0.022kpc is determined.
- ID:
- ivo://CDS.VizieR/J/AJ/162/149
- Title:
- Pulsational changes in classical cepheid X Cygni
- Short Name:
- J/AJ/162/149
- Date:
- 21 Mar 2022 00:19:54
- Publisher:
- CDS
- Description:
- Using an extensive archive for visual observations from the AAVSO, along with published times of maximum light, we determined a new model for the period of X Cygni. The best model is two linear fits for data before and after 1917 (JD2421512). Before that time the period is 16.38438{+/-}0.00036days. After we find a period of 16.386470{+/-}0.000028days. An examination of the O-C values for data after 1917 shows no clear evidence of a constant period change or of sinusoidal variations. The period looks to be constant. From an examination of H-alpha index measurements we find a drop in the value between data before 2013 October and data after 2014 July. This drop is not related to temperature and is likely related to mass loss in the star. Finally, we find that radial-velocity measurements match well with previously published values and show no seasonal variation over the 11yr of data. This again seems to limit the possibility of a companion.