- ID:
- ivo://CDS.VizieR/J/AJ/157/85
- Title:
- The CIDA Variability Survey of Orion OB1. II.
- Short Name:
- J/AJ/157/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of our large-scale, optical, multi-epoch photometric survey across ~180 square degrees in the Orion OB1 association, complemented with extensive follow-up spectroscopy. Our focus is mapping and characterizing the off-cloud, low-mass, pre-main-sequence (PMS) populations. We report 2062 K- and M-type confirmed T Tauri members; 59% are located in the OB1a subassociation, 27% in the OB1b subassociation, and the remaining 14% in the A and B molecular clouds. We characterize two new clusterings of T Tauri stars, the HD 35762 and HR 1833 groups, both located in OB1a not far from the 25 Ori cluster. We also identify two stellar overdensities in OB1b, containing 231 PMS stars, and find that the OB1b region is composed of two populations at different distances, possibly due to the OB1a subassociation overlapping with the front of OB1b. A ~2 deg wide halo of young stars surrounds the Orion Nebula Cluster, corresponding in part to the low-mass populations of NGC 1977 and NGC 1980. We use the strength of H{alpha} in emission, combined with the IR excess and optical variability, to define a new type of T Tauri star, the C/W class, stars we propose may be nearing the end of their accretion phase, in an evolutionary state between classical and weak-lined T Tauri stars. The evolution of the ensemble-wide equivalent width of Li I{lambda}6707 indicates a Li depletion timescale of ~8.5 Myr. Disk accretion declines with an e-folding timescale of ~2 Myr, consistent with previous studies.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/702/506
- Title:
- The Clowes-Campusano LQG Survey. I.
- Short Name:
- J/ApJ/702/506
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The nature of galaxy structures on large scales is a key observational prediction for current models of galaxy formation. The Sloan Digital Sky Survey (SDSS) and the 2dF galaxy survey have revealed a number of structures on 40-150h<SUP>–1</SUP>Mpc scales at low redshifts, and some even larger ones. To constrain galaxy number densities, luminosities, and stellar populations in large structures at higher redshift, we have investigated two sheet-like structures of galaxies at z=0.8 and 1.3 spanning 150h<SUP>–1</SUP> comoving Mpc embedded in large quasar groups (LQGs) extending over at least 200h<SUP>–1</SUP>Mpc. We present first results of an analysis of these sheet-like structures using two contiguous 1° Galaxy Evolution Explorer (GALEX) fields (FUV and NUV) cross-correlated with optical data from the SDSS. We derive a sample of 462 Lyman break galaxy (LBG) candidates coincident with the sheets. Using the GALEX and SDSS data, we show that the overall average spectral energy distribution of a LBG galaxy at z∼1 is flat (in f<SUB>λ</SUB>) in the rest-frame wavelength range from 1500Å to 4000Å, implying evolved populations of stars in the LBGs. From the luminosity functions we get indications for overdensities in the two LQGs compared to their foreground regions.
- ID:
- ivo://CDS.VizieR/I/282
- Title:
- The CMT CCD Drift Scan Survey
- Short Name:
- I/282
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is CMC12 (Version 1.0), an astrometric and photometric catalogue of 6.3 million stars in the red magnitude range 9 to 17. The Carlsberg Meridian Telescope (CMT) underwent a major upgrade in March 1999. A 2k by 2k CCD camera was installed with a Sloan r' filter operating in a drift scan mode. With the new system, the magnitude limit is r'_CMT_=17 and the positional accuracy is about 0.035". The main task of the CMT is to map the sky in the declination range -3{deg} to +30{deg} with the aim of providing an astrometric, and photometric, catalogue that can accurately transfer the Hipparcos/Tycho reference frame to Schmidt plates. The current release (Version 1.0) comprises all the observations made between March 1999 and March 2002 with the new CCD in the declination band -3{deg} to +3{deg}. It is intended to release the rest of the catalogue later. A more complete description is available in the documentation at http://www.ast.cam.ac.uk/~dwe/SRF/cmc12/cmc12_documentation.ps or http://www.ast.cam.ac.uk/~dwe/SRF/cmc12/cmc12_documentation.pdf
1844. The CNOC2 survey. I.
- ID:
- ivo://CDS.VizieR/J/ApJS/129/475
- Title:
- The CNOC2 survey. I.
- Short Name:
- J/ApJS/129/475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Canadian Network for Observational Cosmology Field Galaxy Redshift Survey (CNOC2) obtained spectroscopic redshifts for about 6200 galaxies to a nominal limit of R=21.5. The survey area of about 1.5 square degrees was spread over four patches on the sky. This catalog presents photometry and redshifts for all galaxies in the CNOC2 0223+00 Patch (area of 1409 square arcminutes). A future paper will provide catalogs for the other three patches.
- ID:
- ivo://CDS.VizieR/J/ApJ/819/62
- Title:
- The COSMOS-Legacy Survey (CLS) catalog
- Short Name:
- J/ApJ/819/62
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The COSMOS-Legacy survey is a 4.6Ms Chandra program that has imaged 2.2deg^2^ of the COSMOS field with an effective exposure of ~160ks over the central 1.5deg^2^ and of ~80ks in the remaining area. The survey is the combination of 56 new observations obtained as an X-ray Visionary Project with the previous C-COSMOS survey. We describe the reduction and analysis of the new observations and the properties of 2273 point sources detected above a spurious probability of 2x10^-5^. We also present the updated properties of the C-COSMOS sources detected in the new data. The whole survey includes 4016 point sources (3814, 2920 and 2440 in the full, soft, and hard band). The limiting depths are 2.2x10^-16^, 1.5x10^-15^, and 8.9x10^-16^erg/cm^2^/s in the 0.5-2, 2-10, and 0.5-10keV bands, respectively. The observed fraction of obscured active galactic nuclei with a column density >10^22^/cm^2^ from the hardness ratio (HR) is ~50^+17^_-16_%. Given the large sample we compute source number counts in the hard and soft bands, significantly reducing the uncertainties of 5%-10%. For the first time we compute number counts for obscured (HR>-0.2) and unobscured (HR<-0.2) sources and find significant differences between the two populations in the soft band. Due to the unprecedent large exposure, COSMOS-Legacy area is three times larger than surveys at similar depths and its depth is three times fainter than surveys covering similar areas. The area-flux region occupied by COSMOS-Legacy is likely to remain unsurpassed for years to come.
- ID:
- ivo://CDS.VizieR/J/ApJ/877/81
- Title:
- The C3R2 survey: DR2 new spectroscopic redshifts
- Short Name:
- J/ApJ/877/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Complete Calibration of the Color-Redshift Relation (C3R2) survey is a multi-institution, multi-instrument survey that aims to map the empirical relation of galaxy color to redshift to i~24.5 (AB), thereby providing a firm foundation for weak lensing cosmology with the Stage IV dark energy missions Euclid and WFIRST. Here we present 3171 new spectroscopic redshifts obtained in the 2016B and 2017A semesters with a combination of DEIMOS, LRIS, and MOSFIRE on the Keck telescopes. The observations come from all of the Keck partners: Caltech, NASA, the University of Hawaii, and the University of California. Combined with the 1283 redshifts published in DR1, the C3R2 survey has now obtained and published 4454 high-quality galaxy redshifts. We discuss updates to the survey design and provide a catalog of photometric and spectroscopic data. Initial tests of the calibration method performance are given, indicating that the sample, once completed and combined with extensive data collected by other spectroscopic surveys, should allow us to meet the cosmology requirements for Euclid, and make significant headway toward solving the problem for WFIRST. We use the full spectroscopic sample to demonstrate that galaxy brightness is weakly correlated with redshift once a galaxy is localized in the Euclid or WFIRST color space, with potentially important implications for the spectroscopy needed to calibrate redshifts for faint WFIRST and LSST sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/171/475
- Title:
- The 5C5 survey of radio sources.
- Short Name:
- J/MNRAS/171/475
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains the 5C5 survey of radio sources, one of a series of deep surveys made at 408 MHz (HPBW 80"x109") and 1407 MHz (HPBW 23"x31") with the One-Mile telescope at Cambridge. The 5C5 survey was centered on 09h40m+47d (B1950) and contains 252 sources stronger than 8.7 mJy at 408 MHz and 1.8 mJy at 1407 MHz. The flux densities are on the KPW scale (Kellermann et al. 1969ApJ...157....1K), and were based on 3C48. This table was originally published in Pearson, T.J (1975MNRAS.171..475P)
- ID:
- ivo://CDS.VizieR/II/357
- Title:
- The Dark Energy Survey (DES): Data Release 1
- Short Name:
- II/357
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the first public data release of the Dark Energy Survey, DES DR1, consisting of reduced single-epoch images, co-added images, co-added source catalogs, and associated products and services assembled over the first 3yr of DES science operations. DES DR1 is based on optical/near-infrared imaging from 345 distinct nights (2013 August to 2016 February) by the Dark Energy Camera (DECam) mounted on the 4m Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. We release data from the DES wide-area survey covering ~5000deg^2^ of the southern Galactic cap in five broad photometric bands, grizY. DES DR1 has a median delivered point-spread function of g=1.12, r=0.96, i=0.88, z=0.84, and Y=0.90" FWHM, a photometric precision of <1% in all bands, and an astrometric precision of 151mas. The median co-added catalog depth for a 1.95" diameter aperture at signal-to-noise ratio (S/N)=10 is g=24.33, r=24.08, i=23.44, z=22.69, and Y=21.44mag. DES DR1 includes nearly 400 million distinct astronomical objects detected in ~10000 co-add tiles of size 0.534deg^2^ produced from ~39000 individual exposures. Benchmark galaxy and stellar samples contain ~310 million and ~80 million objects, respectively, following a basic object quality selection. DES DR1 constitutes the largest photometric data set to date at the achieved depth and photometric precision.
- ID:
- ivo://CDS.VizieR/II/371
- Title:
- The Dark Energy Survey (DES): Data Release 2
- Short Name:
- II/371
- Date:
- 31 Jan 2022
- Publisher:
- CDS
- Description:
- We present the second public data release of the Dark Energy Survey, DES DR2, based on optical/near-infrared imaging by the Dark Energy Camera mounted on the 4m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile. DES DR2 consists of reduced single-epoch and coadded images, a source catalog derived from coadded images, and associated data products assembled from 6yr of DES science operations. This release includes data from the DES wide-area survey covering ~5000deg^2^ of the southern Galactic cap in five broad photometric bands, grizY. DES DR2 has a median delivered point-spread function FWHM of g=1.11", r=0.95", i=0.88", z=0.83", and Y=0.90", photometric uniformity with a standard deviation of <3mmag with respect to Gaia DR2 G band, a photometric accuracy of ~11mmag, and a median internal astrometric precision of ~27mas. The median coadded catalog depth for a 1farcs95 diameter aperture at signal-to-noise ratio =10 is g=24.7, r=24.4, i=23.8, z=23.1, and Y=21.7mag. DES DR2 includes ~691 million distinct astronomical objects detected in 10169 coadded image tiles of size 0.534deg^2^ produced from 76217 single-epoch images. After a basic quality selection, benchmark galaxy and stellar samples contain 543 million and 145 million objects, respectively.
1850. The 400d cluster Survey
- ID:
- ivo://CDS.VizieR/J/ApJS/172/561
- Title:
- The 400d cluster Survey
- Short Name:
- J/ApJS/172/561
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of galaxy clusters detected in a new ROSAT PSPC survey. The survey is optimized to sample, at high redshifts, the mass range corresponding to T>5keV clusters at z=0. Technically, our survey is the extension of the 160 square degree survey (160d, Cat. J/ApJ/502/558). We use the same detection algorithm, thus preserving high quality of the resulting sample; the main difference is a significant increase in sky coverage. The new survey covers 397deg^2^ and is based on 1610 high Galactic latitude ROSAT PSPC pointings, virtually all pointed ROSAT data suitable for the detection of distant clusters. The search volume for X-ray luminous clusters within z<1 exceeds that of the entire local universe (z<0.1). We detected 287 extended X-ray sources with fluxes f>1.4x10^-13^ergs/s/cm^2^ in the 0.5-2keV energy band, of which 266 (93%) are optically confirmed as galaxy clusters, groups or individual elliptical galaxies.
