- 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.
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- 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_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://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/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/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/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://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/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.