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2221. VIPERS: galaxy colours and luminosity function
ID:
ivo://CDS.VizieR/J/A+A/563/A92
Title:
VIPERS: galaxy colours and luminosity function
Short Name:
J/A+A/563/A92
Date:
21 Oct 2021
Publisher:
CDS
Description:
We explore the evolution of the colour-magnitude relation (CMR) and luminosity function (LF) at 0.4<z<1.3 from the VIMOS Public Extragalactic Redshift Survey (VIPERS) using ~45000 galaxies with precise spectroscopic redshifts down to i'_AB_<22.5 over ~10.32deg^2^ in two fields. From z=0.5 to z=1.3 the LF and CMR are well defined for different galaxy populations and M^*^_B_ evolves by ~1.04(1.09)+/-0.06(0.10) mag for the total (red) galaxy sample. We compare different criteria for selecting early-type galaxies: (1) a fixed cut in rest-frame (U-V) colours, (2) an evolving cut in (U-V) colours, (3) a rest-frame (NUV-r')-(r'-K) colour selection, and (4) a spectral-energy-distribution classification. The completeness and contamination varies for the different methods and with redshift, but regardless of the method we measure a consistent evolution of the red-sequence (RS). Between 0.4<z<1.3 we find a moderate evolution of the RS intercept of {Delta}(U-V)=0.28+/-0.14 mag, favouring exponentially declining star formation (SF) histories with SF truncation at 1.7<=z<=2.3. Together with the rise in the number density of red galaxies by 0.64dex since z=1, this suggests a rapid build-up of massive galaxies (M_*_>10^11^M_{sun}_) and expeditious RS formation over a short period of ~1.5Gyr starting before z=1. This is supported by the detection of ongoing SF in early-type galaxies at 0.9<z<1.0, in contrast with the quiescent red stellar populations of early-type galaxies at 0.5<z<0.6. There is an increase in the observed CMR scatter with redshift, which is two times larger than observed in galaxy clusters and at variance with theoretical model predictions. We discuss possible physical mechanisms that support the observed evolution of the red galaxy population. Our findings point out that massive galaxies have experienced a sharp SF quenching at z~1 with only limited additional merging. In contrast, less-massive galaxies experience a mix of SF truncation and minor mergers which build-up the low- and intermediate-mass end of the CMR.
2222. VI photometry of Galactic disk field stars
ID:
ivo://CDS.VizieR/J/AcA/60/295
Title:
VI photometry of Galactic disk field stars
Short Name:
J/AcA/60/295
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present OGLE-III Photometric Maps of the Galactic disk fields observed during the OGLE-III campaigns for low luminosity transiting objects that led to the discovery of the first transiting exoplanets. The maps contain precise, calibrated VI photometry of about 9 million stars from 21 OGLE-III fields in the Galactic disk observed in the years 2002-2009 and covering more than 7 square degrees in the sky. Precise astrometry of these objects is also provided. We discuss quality of the data and present a few color-magnitude diagrams of the observed fields.
2223. VIRAC. The VVV Infrared Astrometric Catalogue
ID:
ivo://CDS.VizieR/II/364
Title:
VIRAC. The VVV Infrared Astrometric Catalogue
Short Name:
II/364
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present VIRAC version 1, a near-infrared proper motion and parallax catalogue of the VISTA Variables in the Via Lactea (VVV) survey for 312587642 unique sources averaged across all overlapping pawprint and tile images covering 560deg^2^ of the bulge of the Milky Way and southern disc. The catalogue includes 119 million high-quality proper motion measurements, of which 47 million have statistical uncertainties below 1mas/yr. In the 11<K_s_<14 magnitude range, the high-quality motions have a median uncertainty of 0.67mas/yr. The catalogue also includes 6935 sources with quality-controlled 5{sigma} parallaxes with a median uncertainty of 1.1mas. The parallaxes show reasonable agreement with the Tycho-Gaia Astrometric Solution, though caution is advised for data with modest significance. The SQL data base housing the data is made available via the web. We give example applications for studies of Galactic structure, nearby objects (low-mass stars and brown dwarfs, subdwarfs, white dwarfs) and kinematic distance measurements of young stellar objects. Nearby objects discovered include LTT 7251 B, an L7 benchmark companion to a G dwarf with over 20 published elemental abundances, a bright L subdwarf, VVV 1256-6202, with extremely blue colours and nine new members of the 25pc sample. We also demonstrate why this catalogue remains useful in the era of Gaia. Future versions will be based on profile fitting photometry, use the Gaia absolute reference frame and incorporate the longer time baseline of the VVV extended survey.
2224. VIS3COS. III. Galaxy spectra
ID:
ivo://CDS.VizieR/J/A+A/633/A70
Title:
VIS3COS. III. Galaxy spectra
Short Name:
J/A+A/633/A70
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present spectroscopic observations of 466 galaxies in and around a superstructure at z~0.84 targeted by the VIMOS Spectroscopic Survey of a Supercluster in the COSMOS eld (VIS3COS). We use [OII]3727, H{delta}, and Dn4000 to trace recent, medium-, and long-term star formation histories and investigate the eect of stellar mass and local environment on them. By studying trends in individual and composite galaxy spectra, we find that stellar mass and environment play a role in the observed galactic properties. Galaxies with low stellar mass (10<log10(M*/M_{sun}_)<10.5) in the eld show the strongest H{delta} absorption. Similarly, the massive population (log10(M*/M_{sun}_) > 11) shows an increase in H absorption strengths in intermediate-density environments (e.g. filaments). Galaxies with intermediate stellar mass (10.5<log10(M*/M_{sun}_)<11) have similar H{delta} absorption proles in all environments, but show an indication of enhanced [OII] emission in intermediate-density environments. This indicates that field galaxies with low stellar mass and lament galaxies with high stellar mass are more likely to have experienced a recent burst of star formation, while galaxies of the intermediate stellar-mass show an increase of star formation at lament-like densities. We also find that the median [OII] equivalent width (|EW[OII]|) decreases from 27+/-2{AA} to 2.0^+0,5^_-0.4_{AA} and Dn4000 increases from 1.09+/-0.01 to 1.56+/-0.03 with increasing stellar mass (from ~10^9.25^ to ~10^11.35^M_{sun}_). For the dependence on the environment, we find that at fixed stellar mass, |EW[OII]| is tentatively lower in environments with higher density. We find for Dn4000 that the increase with stellar mass is sharper in denser environments, which indicates that these environments may accelerate galaxy evolution. Moreover, we find higher Dn4000 values in denser environments at fixed stellar mass, suggesting that galaxies are on average older and/or more metal rich in these dense environments. This set of tracers depicts a scenario where the most massive galaxies have, on average, the lowest specic star formation rates and the oldest stellar populations (age>~1Gyr, showing a mass-downsizing eect). We also hypothesize that the observed increase in star formation (higher EW[OII], higher specic star formation rate) at intermediate densities may lead to quenching because we find that the quenched fraction increases sharply from the lament to cluster-like regions at similar stellar masses.
2225. VISION II. VISTA Orion A survey
ID:
ivo://CDS.VizieR/J/A+A/614/A65
Title:
VISION II. VISTA Orion A survey
Short Name:
J/A+A/614/A65
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have investigated the shape of the extinction curve in the infrared up to ~25{mu}m for the Orion A star-forming complex. The basis of this work is near-infrared data acquired with the Visual and Infrared Survey Telescope for Astronomy, in combination with Pan-STARRS and mid-infrared Spitzer photometry. We obtain colour excess ratios for eight passbands by fitting a series of colour-colour diagrams. The fits are performed using Markov chain Monte Carlo methods, together with a linear model under a Bayesian formalism. The resulting colour excess ratios are directly interpreted as a measure of the extinction law. We show that the Orion A molecular cloud is characterized by flat mid-infrared extinction, similar to many other recently studied sightlines. Moreover, we find statistically significant evidence that the extinction law from ~1{mu}m to at least ~6{mu}m varies across the cloud. In particular, we find a gradient along galactic longitude, where regions near the Orion Nebula Cluster show a different extinction law compared to L1641 and L1647, the low-mass star-forming sites in the cloud complex. These variations are of the order of only 3% and are most likely caused by the influence of the massive stars on their surrounding medium. While the observed general trends in our measurements are in agreement with model predictions, both well-established and new dust grain models are not able to fully reproduce our infrared extinction curve. We also present a new extinction map featuring a resolution of 1' and revisit the correlation between extinction and dust optical depth. This analysis shows that cloud substructure, which is not sampled by background sources, affects the conversion factor between these two measures. In conclusion, we argue that specific characteristics of the infrared extinction law are still not well understood, but Orion A can serve as an unbiased template for future studies.
2226. VISION I. VISTA Orion A Survey
ID:
ivo://CDS.VizieR/J/A+A/587/A153
Title:
VISION I. VISTA Orion A Survey
Short Name:
J/A+A/587/A153
Date:
21 Oct 2021
Publisher:
CDS
Description:
Orion A hosts the nearest massive star factory, thus offering a unique opportunity to resolve the processes connected with the formation of both low- and high-mass stars. Here we present the most detailed and sensitive near-infrared (NIR) observations of the entire molecular cloud to date. With the unique combination of high image quality, survey coverage, and sensitivity, our NIR survey of Orion A aims at establishing a solid empirical foundation for further studies of this important cloud. In this first paper we present the observations, data reduction, and source catalog generation. To demonstrate the data quality, we present a first application of our catalog to estimate the number of stars currently forming inside Orion A and to verify the existence of a more evolved young foreground population. We used the European Southern Observatory's (ESO) Visible and Infrared Survey Telescope for Astronomy (VISTA) to survey the entire Orion A molecular cloud in the NIR J, H, and K_S_ bands, covering a total of ~18.3deg^2^. We implemented all data reduction recipes independently of the ESO pipeline. Estimates of the young populations toward Orion A are derived via the K_S_-band luminosity function. Our catalog (799995 sources) increases the source counts compared to the Two Micron All Sky Survey by about an order of magnitude. The 90% completeness limits are 20.4, 19.9, and 19.0mag in J, H, and K_S_, respectively. The reduced images have 20% better resolution on average compared to pipeline products. We find between 2300 and 3000 embedded objects in Orion A and confirm that there is an extended foreground population above the Galactic field, in agreement with previous work. The Orion A VISTA catalog represents the most detailed NIR view of the nearest massive star-forming region and provides a fundamental basis for future studies of star formation processes toward Orion.
2227. VISTA and Subaru/HSC obs. of Upper Scorpius
ID:
ivo://CDS.VizieR/J/MNRAS/503/2265
Title:
VISTA and Subaru/HSC obs. of Upper Scorpius
Short Name:
J/MNRAS/503/2265
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim at identifying very low-mass isolated planetary-mass member candidates in the nearest OB association to the Sun, Upper Scorpius (145pc; 5-10Myr), to constrain the form and shape of the luminosity function and mass spectrum in this regime. We conducted a deep multi-band (Y=21.2, J=20.5, Z=22.0mag) photometric survey of six square degrees in the central region of Upper Scorpius. We extend the current sequence of astrometric and spectroscopic members by about two magnitudes in Y and one magnitude in J, reaching potentially T-type free-floating members in the association with predicted masses below 5 Jupiter masses, well into the planetary-mass regime. We extracted a sample of 57 candidates in this area and present infrared spectroscopy confirming two of them as young L-type members with characteristic spectral features of 10Myr-old brown dwarfs. Among the 57 candidates, we highlight 10 new candidates fainter than the coolest members previously confirmed spectroscopically. We do not see any obvious sign of decrease in the mass spectrum of the association, suggesting that star processes can form substellar objects with masses down to 4-5 Jupiter masses.
2228. VISTA Deep Extragalactic Observations (VIDEO)
ID:
ivo://CDS.VizieR/III/334
Title:
VISTA Deep Extragalactic Observations (VIDEO)
Short Name:
III/334
Date:
21 Oct 2021
Publisher:
CDS
Description:
VIDEO is a ~12 square degrees survey in the near-infrared Z, Y, J, H and Ks bands,over the ELAIS-S1, XMMLS, and ECDFS extragalactic fields. This document describes the catalog released for the deep stracked data in the VIDEO-XMM3 field, which also covers the Canada-France-Hawaii Telescope Legacy Survey Deep-1 field (CFHTLS-D1).
2229. Vista Hemisphere Survey ConeSearch
ID:
ivo://archive.stsci.edu/catalogs/vistavhs
Title:
Vista Hemisphere Survey ConeSearch
Short Name:
VISTA VHS CS
Date:
13 Feb 2020 17:43:47
Publisher:
Space Telescope Science Institute Archive
Description:
All MAST catalog holdings are available via Cone Search endpoints. This service provides access to the MAST copy of the VISTA Hemisphere Survey All available missions are listed at http://archive.stsci.edu/vo/mast_services.html.
2230. VISTA IR photometry of {sigma} Ori cluster
ID:
ivo://CDS.VizieR/J/ApJ/754/30
Title:
VISTA IR photometry of {sigma} Ori cluster
Short Name:
J/ApJ/754/30
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on our analysis of the VISTA Orion ZY JHK_s_ photometric data (completeness magnitudes of Z=22.6 and J=21.0 mag) focusing on a circular area of 2798.4arcmin^2^ around the young {sigma} Orionis star cluster (~3Myr, ~352pc, and solar metallicity). The combination of the VISTA photometry with optical, WISE and Spitzer data allows us to identify a total of 210 {sigma} Orionis member candidates with masses in the interval 0.25-0.004M_{sun}_, 23 of which are new planetary-mass object findings. These discoveries double the number of cluster planetary-mass candidates known so far. One object has colors compatible with a T spectral type. The {sigma} Orionis cluster harbors about as many brown dwarfs (69, 0.072-0.012M_{sun}_) and planetary-mass objects (37, 0.012-0.004M_{sun}_) as very low mass stars (104, 0.25-0.072M_{sun}_). Based on Spitzer data, we derive a disk frequency of ~40% for very low mass stars, brown dwarfs, and planetary-mass objects in {sigma} Orionis. The radial density distributions of these three mass intervals are alike: all are spatially concentrated within an effective radius of 12' (1.2pc) around the multiple star {sigma} Ori, and no obvious segregation between disk-bearing and diskless objects is observed.

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