- ID:
- ivo://CDS.VizieR/J/MNRAS/327/23
- Title:
- CCD UBVRI photometry of 7 open star clusters
- Short Name:
- J/MNRAS/327/23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We derive cluster parameters and mass functions from new UBVRI CCD photometric observations of ~3500 stars reaching down to V~20mag for the distant southern open star clusters NGC 3105, NGC 3603, Melotte 105, Hogg 15, NGC 4815, Pismis 20 and NGC 6253. For NGC 3105 and Hogg 15, CCD data are presented for the first time. The observations were carried out in 1992 between February 28 and March 8, June 5 and 9, and July 9 and 12 in the Cousins U, B, V, R and I photometric bands using CCD detector at the 1.0-m Elizabeth Telescope at the South African Astronomical Observatory (SAAO), Sutherland.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/518/262
- Title:
- CCD VIc Photometry of M30 Stars
- Short Name:
- J/ApJ/518/262
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The file contains VIc data of the globular cluster M30. All frames were taken using a 2048x2048 pixel CCD with pixels covering 0.44 arcseconds on a side, for a total field of approximately 15 arcminutes on a side. Data were taken on 1994 July 78 at the Cerro Tololo Inter-American Observatory (CTIO) 4m telescope. The data were calibrated against Landolt (1983, Cat. <II/118>) standard stars.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/2948
- Title:
- Ccompact group galaxies UV and IR SFR
- Short Name:
- J/MNRAS/459/2948
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Compact groups of galaxies provide insight into the role of low-mass, dense environments in galaxy evolution because the low velocity dispersions and close proximity of galaxy members result in frequent interactions that take place over extended time-scales. We expand the census of star formation in compact group galaxies by Tzanavaris et al. (2010, Cat. J/ApJS/212/9) and collaborators with Swift UVOT, Spitzer IRAC and MIPS 24{mu}m photometry of a sample of 183 galaxies in 46 compact groups. After correcting luminosities for the contribution from old stellar populations, we estimate the dust-unobscured star formation rate (SFR_UV_) using the UVOT uvw2 photometry. Similarly, we use the MIPS 24 {mu}m photometry to estimate the component of the SFR that is obscured by dust (SFR_IR_). We find that galaxies which are MIR-active (MIR-'red'), also have bluer UV colours, higher specific SFRs, and tend to lie in HI-rich groups, while galaxies that are MIR-inactive (MIR-'blue') have redder UV colours, lower specific SFRs, and tend to lie in HI-poor groups. We find the SFRs to be continuously distributed with a peak at about 1M_{sun}_/yr, indicating this might be the most common value in compact groups. In contrast, the specific SFR distribution is bimodal, and there is a clear distinction between star-forming and quiescent galaxies. Overall, our results suggest that the specific SFR is the best tracer of gas depletion and galaxy evolution in compact groups.
- ID:
- ivo://CDS.VizieR/J/ApJ/817/34
- Title:
- C-COSMOS Legacy sources multiwavelength catalog
- Short Name:
- J/ApJ/817/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalog of optical and infrared counterparts of the Chandra COSMOS-Legacy Survey, a 4.6Ms Chandra program on the 2.2deg^2^ of the COSMOS field, combination of 56 new overlapping observations obtained in Cycle 14 with the previous C-COSMOS survey. In this Paper we report the i, K, and 3.6{mu}m identifications of the 2273 X-ray point sources detected in the new Cycle 14 observations. We use the likelihood ratio technique to derive the association of optical/infrared (IR) counterparts for 97% of the X-ray sources. We also update the information for the 1743 sources detected in C-COSMOS, using new K and 3.6{mu}m information not available when the C-COSMOS analysis was performed. The final catalog contains 4016 X-ray sources, 97% of which have an optical/IR counterpart and a photometric redshift, while ~54% of the sources have a spectroscopic redshift. The full catalog, including spectroscopic and photometric redshifts and optical and X-ray properties described here in detail, is available online. We study several X-ray to optical (X/O) properties: with our large statistics we put better constraints on the X/O flux ratio locus, finding a shift toward faint optical magnitudes in both soft and hard X-ray band. We confirm the existence of a correlation between X/O and the the 2-10keV luminosity for Type 2 sources. We extend to low luminosities the analysis of the correlation between the fraction of obscured AGNs and the hard band luminosity, finding a different behavior between the optically and X-ray classified obscured fraction.
- ID:
- ivo://CDS.VizieR/II/332
- Title:
- c2d Spitzer final data release (DR4)
- Short Name:
- II/332
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Crucial steps in the formation of stars and planets can be studied only at mid- to far-infrared wavelengths, where the Space Infrared Telescope (SIRTF) provides an unprecedented improvement in sensitivity. We will use all three SIRTF instruments (Infrared Array Camera [IRAC], Multiband Imaging Photometer for SIRTF [MIPS], and Infrared Spectrograph [IRS]) to observe sources that span the evolutionary sequence from molecular cores to protoplanetary disks, encompassing a wide range of cloud masses, stellar masses, and star-forming environments. In addition to targeting about 150 known compact cores, we will survey with IRAC and MIPS (3.6-70{mu}m) the entire areas of five of the nearest large molecular clouds for new candidate protostars and substellar objects as faint as 0.001 solar luminosities. We will also observe with IRAC and MIPS about 190 systems likely to be in the early stages of planetary system formation (ages up to about 10Myr), probing the evolution of the circumstellar dust, the raw material for planetary cores. Candidate planet-forming disks as small as 0.1 lunar masses will be detectable. Spectroscopy with IRS of new objects found in the surveys and of a select group of known objects will add vital information on the changing chemical and physical conditions in the disks and envelopes. The resulting data products will include catalogs of thousands of previously unknown sources, multiwavelength maps of about 20deg^2^ of molecular clouds, photometry of about 190 known young stars, spectra of at least 170 sources, ancillary data from ground-based telescopes, and new tools for analysis and modeling. These products will constitute the foundations for many follow-up studies with ground-based telescopes, as well as with SIRTF itself and other space missions such as SIM, JWST, Herschel, and TPF/Darwin.
- ID:
- ivo://CDS.VizieR/J/ApJS/251/2
- Title:
- CDWFS: Chandra survey in Bootes. I. X-ray cat.
- Short Name:
- J/ApJS/251/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new, ambitious survey performed with the Chandra X-ray Observatory of the 9.3deg^2^ Bootes field of the NOAO Deep Wide-Field Survey. The wide field probes a statistically representative volume of the universe at high redshift. The Chandra Deep Wide-field Survey exploits the excellent sensitivity and angular resolution of Chandra over a wide area, combining 281 observations spanning 15yr, for a total exposure time of 3.4Ms, and detects 6891 X-ray point sources down to limiting fluxes of 4.7x10^-16^, 1.5x10^-16^, and 9x10^-16^erg/cm^2^/s in the 0.5-7, 0.5-2, and 2-7keV bands, respectively. The robustness and reliability of the detection strategy are validated through extensive, state-of-the-art simulations of the whole field. Accurate number counts, in good agreement with previous X-ray surveys, are derived thanks to the uniquely large number of point sources detected, which resolve 65.0%+/-12.8% of the cosmic X-ray background between 0.5 and 2keV and 81.0%+/-11.5% between 2 and 7keV. Exploiting the wealth of multiwavelength data available on the field, we assign redshifts to ~94% of the X-ray sources, estimate their obscuration, and derive absorption-corrected luminosities.
- ID:
- ivo://CDS.VizieR/J/MNRAS/366/1265
- Title:
- CENSORS infrared imaging
- Short Name:
- J/MNRAS/366/1265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Combined EIS-NVSS Survey of Radio Sources (CENSORS) is a 1.4-GHz radio survey selected from the National Radio Astronomy Observatories (NRAO) Very Large Array (VLA) Sky Survey (NVSS) and complete to a flux density of 7.2mJy. It targets the European Southern Observatory (ESO) Imaging Survey (EIS) Patch D, which is a 3x2{deg}^2^ field centred on right ascension 09:51:36.0 and declination 21:00:00 (J2000). This paper presents K-band imaging of 142 of the 150 CENSORS sources. The primary motivation for beginning infrared imaging of the sample was to identify the host galaxies of ~30 per cent of sources for which the EIS I-band imaging failed to produce a likely candidate. In addition, K-band magnitudes allow photometric redshift estimation and IK colours aid the identification of host galaxies (which are typically old, red ellipticals). Of the sources observed in the I and K bands, four remain undetected, possibly indicating high redshifts for the host galaxies, and eight involve complicated radio structures, or several candidate host galaxies, which have yet to be resolved. Thus, the host galaxy identifications are brought to 92 per cent completeness.
- ID:
- ivo://CDS.VizieR/J/ApJS/219/19
- Title:
- Census of nearby white dwarfs from SUPERBLINK
- Short Name:
- J/ApJS/219/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a detailed description of the physical properties of our current census of white dwarfs within 40pc of the Sun, based on an exhaustive spectroscopic survey of northern hemisphere candidates from the SUPERBLINK proper motion database. Our method for selecting white dwarf candidates is based on a combination of theoretical color-magnitude relations and reduced proper motion diagrams. We reported in an earlier publication the discovery of nearly 200 new white dwarfs, and we present here the discovery of an additional 133 new white dwarfs, among which we identify 96 DA, 3 DB, 24 DC, 3 DQ, and 7 DZ stars. We further identify 178 white dwarfs that lie within 40pc of the Sun, representing a 40% increase of the current census, which now includes 492 objects. We estimate the completeness of our survey at between 66% and 78%, allowing for uncertainties in the distance estimates. We also perform a homogeneous model atmosphere analysis of this 40pc sample and find a large fraction of massive white dwarfs, indicating that we are successfully recovering the more massive, and less luminous objects often missed in other surveys. We also show that the 40pc sample is dominated by cool and old white dwarfs, which populate the faint end of the luminosity function, although trigonometric parallaxes will be needed to shape this part of the luminosity function more accurately. Finally, we identify 4 probable members of the 20pc sample, 4 suspected double degenerate binaries, and we also report the discovery of two new ZZ Ceti pulsators.
- ID:
- ivo://CDS.VizieR/J/ApJ/715/1094
- Title:
- Census of self-obscured massive stars
- Short Name:
- J/ApJ/715/1094
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A new link in the causal mapping between massive stars and potentially fatal explosive transients opened with the 2008 discovery of the dust-obscured progenitors of the luminous outbursts in NGC 6946 and NGC 300. Here, we carry out a systematic mid-IR photometric search for massive, luminous, and self-obscured stars in four nearby galaxies: M33, NGC 300, M81, and NGC 6946. For detection, we use only the 3.6um and 4.5um IRAC bands, as these can still be used for multi-epoch Spitzer surveys of nearby galaxies (<~10Mpc). We combine familiar point-spread function and aperture photometry with an innovative application of image subtraction to catalog the self-obscured massive stars in these galaxies. In particular, we verify that stars analogous to the progenitors of the NGC 6946 (SN 2008S) and NGC 300 transients are truly rare in all four galaxies: their number may be as low as ~1 per galaxy at any given moment. This result empirically supports the idea that the dust-enshrouded phase is a very short lived phenomenon in the lives of many massive stars and that these objects constitute a natural extension of the asymptotic giant branch sequence. We also provide mid-IR catalogs of sources in NGC 300, M81, and NGC 6946.
- ID:
- ivo://CDS.VizieR/J/ApJ/880/7
- Title:
- Census of the Local Universe survey. I. CLU-Halpha
- Short Name:
- J/ApJ/880/7
- Date:
- 03 Nov 2021 07:51:08
- Publisher:
- CDS
- Description:
- We present the Census of the Local Universe (CLU) narrowband survey to search for emission-line (H{alpha}) galaxies. CLU-H{alpha} has imaged ~3{pi} of the sky (26470deg^2^) with four narrowband filters that probe a distance out to 200Mpc. We have obtained spectroscopic follow-up for galaxy candidates in 14 preliminary fields (101.6deg^2^) to characterize the limits and completeness of the survey. In these preliminary fields, CLU can identify emission lines down to an H{alpha} flux limit of 10^-14^erg/s/cm^2^ at 90% completeness, and recovers 83% (67%) of the H{alpha} flux from cataloged galaxies in our search volume at the {Sigma}=2.5 ({Sigma}=5) color excess levels. The contamination from galaxies with no emission lines is 61% (12%) for {Sigma}=2.5 ({Sigma}=5). Also, in the regions of overlap between our preliminary fields and previous emission-line surveys, we recover the majority of the galaxies found in previous surveys and identify an additional ~300 galaxies. In total, we find 90 galaxies with no previous distance information, several of which are interesting objects: 7 blue compact dwarfs, 1 green pea, and a Seyfert galaxy; we also identify a known planetary nebula. These objects show that the CLU-H{alpha} survey can be a discovery machine for objects in our own Galaxy and extreme galaxies out to intermediate redshifts. However, the majority of the CLU-H{alpha} galaxies identified in this work show properties consistent with normal star-forming galaxies. CLU-H{alpha} galaxies with new redshifts will be added to existing galaxy catalogs to focus the search for the electromagnetic counterpart to gravitational wave events.
