Search

Start Over Subject surveys Rights public
631. Galaxy groups in the VIMOS-VLT Deep Survey
ID:
ivo://CDS.VizieR/J/A+A/520/A42
Title:
Galaxy groups in the VIMOS-VLT Deep Survey
Short Name:
J/A+A/520/A42
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a homogeneous and complete catalogue of optical galaxy groups identified in the VIMOS-VLT Deep Survey (VVDS). We use mock catalogues extracted from the Millennium Simulation to study the potential systematics that might affect the overall distribution of the identified systems, and also to asses how well galaxy redshifts trace the line-of-sight velocity dispersion of the underlying mass overdensity. We train on these mock catalogues the adopted group-finding technique (the Voronoi-Delaunay Method, VDM), to recover in a robust and unbiased way the redshift and velocity dispersion distributions of groups and maximize the level of completeness (C) and purity (P) of the group catalogue. We identify 318(/144) VVDS groups with at least 2(/3) members within 0.2<=z<=1.0, globally with C=60% and P=50%. We use the group sample to study the redshift evolution of the fraction f_b_ of blue galaxies (U-B<=1) within 0.2<=z<=1 in both groups and in the whole ensemble of galaxies irrespectively of their environment.
632. Galaxy morphology in the CFRS
ID:
ivo://CDS.VizieR/J/AJ/122/621
Title:
Galaxy morphology in the CFRS
Short Name:
J/AJ/122/621
Date:
21 Oct 2021
Publisher:
CDS
Description:
The images of 229 galaxies in the Canada-France Redshift Survey have been classified on the DDO system. These observations were combined with previous classifications of galaxies with known redshifts in the Hubble Deep Field. The combined sample provides homogeneous morphological classifications for 425 galaxies of known redshift. The fraction of all galaxies that are of type E, S0, or E/S0 appears to remain approximately constant at ~17% over the redshift range 0.25<z<1.2. Over the same range, the fraction of irregular (Ir) galaxies increases from ~5% to ~12%. Part of this increase may be due to mild luminosity evolution of Ir galaxies. The frequency of mergers is found to rise by a factor of 2 or 3 over the redshift range covered by the present survey. These results are in qualitative agreement with those obtained previously by Brinchmann et al. (Cat. <J/ApJ/499/112>) using a coarser galaxy classification system.
633. Galaxy redshift survey in a Coma strip
ID:
ivo://CDS.VizieR/J/MNRAS/243/390
Title:
Galaxy redshift survey in a Coma strip
Short Name:
J/MNRAS/243/390
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
634. Galaxy stellar and baryonic mass functions
ID:
ivo://CDS.VizieR/J/ApJ/824/124
Title:
Galaxy stellar and baryonic mass functions
Short Name:
J/ApJ/824/124
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this work, we present galaxy stellar and baryonic (stars plus cold gas) mass functions (SMF and BMF) and their halo mass dependence for two volume-limited data sets. The first, RESOLVE-B, coincides with the Stripe 82 footprint and is extremely complete down to baryonic mass M_bary_~10^9.1^M_{sun}_, probing the gas-rich dwarf regime below M_bary_~10^10^M_{sun}_. The second, ECO, covers a ~40x larger volume (containing RESOLVE-A) and is complete to M_bary_~10^9.4^M_{sun}_. To construct the SMF and BMF we implement a new "cross-bin sampling" technique with Monte Carlo sampling from the full likelihood distributions of stellar or baryonic mass. Our SMFs exhibit the "plateau" feature starting below M_star_~10^10^M_{sun}_ that has been described in prior work. However, the BMF fills in this feature and rises as a straight power law below ~10^10^M_{sun}_, as gas-dominated galaxies become the majority of the population. Nonetheless, the low-mass slope of the BMF is not as steep as that of the theoretical dark matter halo MF. Moreover, we assign group halo masses by abundance matching, finding that the SMF and BMF, separated into four physically motivated halo mass regimes, reveal complex structure underlying the simple shape of the overall MFs. In particular, the satellite MFs are depressed below the central galaxy MF "humps" in groups with mass<10^13.5^M_{sun}_ yet rise steeply in clusters. Our results suggest that satellite destruction and stripping are active from the point of nascent group formation. We show that the key role of groups in shaping MFs enables reconstruction of a given survey's SMF or BMF based on its group halo mass distribution.
635. Galaxy survey in 3 QSO fields
ID:
ivo://CDS.VizieR/J/ApJ/701/1219
Title:
Galaxy survey in 3 QSO fields
Short Name:
J/ApJ/701/1219
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an imaging and spectroscopic survey of galaxies in fields around QSOs HE 0226-4110, PKS 0405-123, and PG 1216+069. The fields are selected to have ultraviolet echelle spectra available, which uncover 195 Ly{alpha} absorbers and 13 OVI absorbers along the three sightlines. We obtain robust redshifts for 1104 galaxies of rest-frame absolute magnitude M_R_-5logh<~-16 and at projected physical distances {rho}<~4h^-1^Mpc from the QSOs. Hubble Space Telescope (HST)/WFPC2 images of the fields around PKS 0405-123 and PG 1216+069 are available for studying the optical morphologies of absorbing galaxies. Combining the absorber and galaxy data, we perform a cross-correlation study to understand the physical origin of Ly{alpha} and OVI absorbers and to constrain the properties of extended gas around galaxies.
636. Galaxy Zoo 2: new classification
ID:
ivo://CDS.VizieR/J/MNRAS/461/3663
Title:
Galaxy Zoo 2: new classification
Short Name:
J/MNRAS/461/3663
Date:
21 Oct 2021
Publisher:
CDS
Description:
The majority of galaxies in the local Universe exhibit spiral structure with a variety of forms. Many galaxies possess two prominent spiral arms, some have more, while others display a many-armed flocculent appearance. Spiral arms are associated with enhanced gas content and star formation in the discs of low-redshift galaxies, so are important in the understanding of star formation in the local universe. As both the visual appearance of spiral structure, and the mechanisms responsible for it vary from galaxy to galaxy, a reliable method for defining spiral samples with different visual morphologies is required. In this paper, we develop a new debiasing method to reliably correct for redshift-dependent bias in Galaxy Zoo 2, and release the new set of debiased classifications. Using these, a luminosity-limited sample of ~18000 Sloan Digital Sky Survey spiral galaxies is defined, which are then further sub-categorized by spiral arm number. In order to explore how different spiral galaxies form, the demographics of spiral galaxies with different spiral arm numbers are compared. It is found that whilst all spiral galaxies occupy similar ranges of stellar mass and environment, many-armed galaxies display much bluer colours than their two-armed counterparts. We conclude that two-armed structure is ubiquitous in star-forming discs, whereas many-armed spiral structure appears to be a short-lived phase, associated with more recent, stochastic star-formation activity.
637. GALEX and Gaia data for APOGEE red clump stars
ID:
ivo://CDS.VizieR/J/ApJ/872/95
Title:
GALEX and Gaia data for APOGEE red clump stars
Short Name:
J/ApJ/872/95
Date:
21 Oct 2021
Publisher:
CDS
Description:
Although core helium-burning red clump (RC) stars are faint at ultraviolet wavelengths, their ultraviolet (UV)-optical color is a unique and accessible probe of their physical properties. Using data from the Galaxy Evolution Explorer All Sky Imaging Survey (GALEX AIS), Gaia Data Release 2, and the Sloan Digital Sky Survey Apache Point Observatory Galactic Evolution Experiment (APOGEE) DR14 survey, we find that spectroscopic metallicity is strongly correlated with the location of an RC star in the UV-optical color-magnitude diagram. The RC has a wide spread in (NUV-G)_0_ color of over 4mag compared to a 0.7mag range in (G_BP_-G_RP_)_0_. We propose a photometric, dust-corrected, UV-optical (NUV-G)_0_ color-metallicity [Fe/H] relation using a sample of 5175 RC stars from APOGEE. We show that this relation has a scatter of 0.16dex and is easier to obtain for large, wide-field samples than for spectroscopic metallicities. Importantly, the effect may be comparable to the spread in RC color attributed to extinction in other studies.
638. GALEX Arecibo SDSS survey. Final data release
ID:
ivo://CDS.VizieR/J/MNRAS/436/34
Title:
GALEX Arecibo SDSS survey. Final data release
Short Name:
J/MNRAS/436/34
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the final data release from the GALEX Arecibo SDSS Survey (GASS), a large Arecibo programme that measured the HI properties for an unbiased sample of ~800 galaxies with stellar masses greater than 10^10^M_{sun}_ and redshifts 0.025<z<0.05. This release includes new Arecibo observations for 250 galaxies. We use the full GASS sample to investigate environmental effects on the cold gas content of massive galaxies at fixed stellar mass. The environment is characterized in terms of dark matter halo mass, obtained by cross-matching our sample with the Sloan Digital Sky Survey (SDSS) group catalogue of Yang et al. Our analysis provides, for the first time, clear statistical evidence that massive galaxies located in haloes with masses of 10^13^-10^14^M_{sun}_ have at least 0.4dex less HI than objects in lower density environments. The process responsible for the suppression of gas in group galaxies most likely drives the observed quenching of the star formation in these systems. Our findings strongly support the importance of the group environment for galaxy evolution, and have profound implications for semi-analytic models of galaxy formation, which currently do not allow for stripping of the cold interstellar medium in galaxy groups.
639. GALEX EUV quasar colours of SDSS QSOs DR14
ID:
ivo://CDS.VizieR/J/MNRAS/493/2745
Title:
GALEX EUV quasar colours of SDSS QSOs DR14
Short Name:
J/MNRAS/493/2745
Date:
21 Oct 2021
Publisher:
CDS
Description:
The rest-frame far to extreme ultraviolet (UV) colour-redshift relationship has been constructed from data on over 480,000 quasars carefully cross-matched between SDSS Data Release 14 and the final GALEX photometric catalog. UV matching and detection probabilities are given for all the quasars, including dependencies on separation, optical brightness, and redshift. Detection limits in the UV bands are also provided for all objects. The UV colour distributions are skewed redward at virtually all redshifts, especially when detection limits are accounted for. The median GALEX far-UV minus near-UV (FUV-NUV) colour-redshift relation is reliably determined up to z~2.8, corresponding to rest-frame wavelengths as short as 400{AA}. Extreme-UV (EUV) colours are substantially redder than found previously, when detection limits are properly accounted for. Quasar template spectra were forward modeled through the GALEX bandpasses, accounting for intergalactic opacity, intrinsic reddening, and continuum slope variations. Intergalactic absorption by itself cannot account for the very red EUV colours. The colour-redshift relation is consistent with no intrinsic reddening, at least for SMC-like extinction. The best model fit has a far-UV continuum power-law slope of -0.34+/-0.03 consistent with previous results, but an EUV slope of -2.90+/-0.04 that is much redder and inconsistent with any previous composite value (all >-2.0). The EUV slope difference can be attributed in part to the tendency of previous studies to preferentially select UV brighter and bluer objects. The weak EUV flux suggests quasar accretion disc models that include outflows such as disc winds.
640. GALEX/SDSS quasar catalog
ID:
ivo://CDS.VizieR/J/AJ/133/1780
Title:
GALEX/SDSS quasar catalog
Short Name:
J/AJ/133/1780
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the broadband UV and optical properties of z~<3.4 quasars matched in the Galaxy Evolution Explorer (GALEX) General Data Release 1 (GR1) and the Sloan Digital Sky Survey (SDSS) Data Release 3 (DR3). Of the 6371 SDSS DR3 quasars covered by 204 GALEX GR1 tiles, 5380 (84%) have near-UV detections, while 3034 (48%) have both near-UV and far-UV detections using a matching radius of 7". Most of the DR3 sample quasars are detected in the near-UV until z~1.7, with the near-UV detection fraction dropping to ~50% by z~2.