- ID:
- ivo://CDS.VizieR/J/MNRAS/413/971
- Title:
- Galaxy And Mass Assembly (GAMA) DR1
- Short Name:
- J/MNRAS/413/971
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galaxy and Mass Assembly (GAMA) survey has been operating since 2008 February on the 3.9-m Anglo-Australian Telescope using the AAOmega fibre-fed spectrograph facility to acquire spectra with a resolution of R~1300 for 120862 Sloan Digital Sky Survey selected galaxies. The target catalogue constitutes three contiguous equatorial regions centred at 9h (G09), 12h (G12) and 14.5h (G15) each of 12x4deg^2^ to limiting fluxes of r_pet_<19.4, r_pet_<19.8 and r_pet_<19.4 mag, respectively (and additional limits at other wavelengths). Spectra and reliable redshifts have been acquired for over 98 per cent of the galaxies within these limits. Here we present the survey footprint, progression, data reduction, redshifting, re-redshifting, an assessment of data quality after 3yr, additional image analysis products (including ugrizYJHK photometry, Sersic profiles and photometric redshifts), observing mask and construction of our core survey catalogue (GamaCore). From this we create three science-ready catalogues: GamaCoreDR1 for public release, which includes data acquired during year 1 of operations within specified magnitude limits (2008 February to April); GamaCoreMainSurvey containing all data above our survey limits for use by the GAMA Team and collaborators; and GamaCoreAtlasSV containing year 1, 2 and 3 data matched to Herschel-ATLAS science demonstration data. These catalogues along with the associated spectra, stamps and profiles can be accessed via the GAMA website: http://www.gama-survey.org/
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/2144
- Title:
- Galaxy And Mass Assembly: red & blue galaxies
- Short Name:
- J/MNRAS/446/2144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure the mass functions for generically red and blue galaxies, using a z<0.12 sample of logM_*_>8.7 field galaxies from the Galaxy And Mass Assembly (GAMA) survey. Our motivation is that, as we show, the dominant uncertainty in existing measurements stems from how "red" and "blue" galaxies have been selected/defined. Accordingly, we model our data as two naturally overlapping populations, each with their own mass function and colour-mass relation, which enables us characterize the two populations without having to specify a priori which galaxies are "red" and "blue". Our results then provide the means to derive objective operational definitions for the terms "red" and "blue", which are based on the phenomenology of the colour-mass diagrams. Informed by this descriptive modelling, we show that (1) after accounting for dust, the stellar colours of "blue" galaxies do not depend strongly on mass; (2) the tight, flat "dead sequence" does not extend much below logM_*_~10.5; instead, (3) the stellar colours of "red" galaxies vary rather strongly with mass, such that lower mass "red" galaxies have bluer stellar populations; (4) below logM_*_~9.3, the "red" population dissolves into obscurity, and it becomes problematic to talk about two distinct populations; as a consequence, (5) it is hard to meaningfully constrain the shape, including the existence of an upturn, of the "red" galaxy mass function below logM_*_~9.3. Points 1-4 provide meaningful targets for models of galaxy formation and evolution to aim for.
- ID:
- ivo://CDS.VizieR/J/ApJ/733/L47
- Title:
- Galaxy bulge types within 11Mpc
- Short Name:
- J/ApJ/733/L47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an inventory of galaxy bulge types (elliptical galaxy, classical bulge, pseudobulge, and bulgeless galaxy) in a volume-limited sample within the local 11Mpc sphere using Spitzer 3.6um and Hubble Space Telescope data. We find that whether counting by number, star formation rate, or stellar mass, the dominant galaxy type in the local universe has pure disk characteristics (either hosting a pseudobulge or being bulgeless). Galaxies that contain either a pseudobulge or no bulge combine to account for over 80% of the number of galaxies above a stellar mass of 10^9^M_{sun}_. Classical bulges and elliptical galaxies account for ~1/4, and disks for ~3/4 of the stellar mass in the local 11Mpc. About 2/3 of all star formation in the local volume takes place in galaxies with pseudobulges. Looking at the fraction of galaxies with different bulge types as a function of stellar mass, we find that the frequency of classical bulges strongly increases with stellar mass, and comes to dominate above 10^10.5^M_{sun}_. Galaxies with pseudobulges dominate at 10^9.5^-10^10.5^M_{sun}_. Yet lower-mass galaxies are most likely to be bulgeless. If pseudobulges are not a product of mergers, then the frequency of pseudobulges in the local universe poses a challenge for galaxy evolution models.
- ID:
- ivo://CDS.VizieR/J/AJ/144/127
- Title:
- 204 galaxy candidates from VVV infrared photometry
- Short Name:
- J/AJ/144/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- VISTA Variables in the Via Lactea (VVV) is an ESO variability survey that is performing observations in near-infrared bands (ZY JHK_s_) toward the Galactic bulge and part of the disk with the completeness limits at least 3mag deeper than Two Micron All Sky Survey. In the present work, we searched in the VVV survey data for background galaxies near the Galactic plane using ZY JHK_s_ photometry that covers 1.636deg^2^. We identified 204 new galaxy candidates by analyzing colors, sizes, and visual inspection of multi-band (ZY JHK_s_) images. The galaxy candidate colors were also compared with the predicted ones by star count models considering a more realistic extinction model at the same completeness limits observed by VVV. A comparison of the galaxy candidates with the expected one by Millennium simulations is also presented. Our results increase the number density of known galaxies behind the Milky Way by more than one order of magnitude. A catalog with galaxy properties including ellipticity, Petrosian radii, and ZY JHK_s_magnitudes is provided, as well as comparisons of the results with other surveys of galaxies toward the Galactic plane.
- ID:
- ivo://CDS.VizieR/J/ApJ/820/98
- Title:
- Galaxy candidates in the Hubble Frontier Fields
- Short Name:
- J/ApJ/820/98
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we present the results of our search for and study of z>~6 galaxy candidates behind the third Frontier Fields (FFs) cluster, MACS J0717.5+3745, and its parallel field, combining data from Hubble and Spitzer. We select 39 candidates using the Lyman break technique, for which the clear non-detection in optical make the extreme mid-z interlopers hypothesis unlikely. We also take benefit from z>~6 samples selected using the previous FF data sets of Abell 2744 and MACS 0416 to improve the constraints on the properties of very high redshift objects. We compute the redshift and the physical properties such emission lines properties, star formation rate, reddening, and stellar mass for all FF objects from their spectral energy distribution using templates including nebular emission lines. We study the relationship between several physical properties and confirm the trend already observed in previous surveys for evolution of star formation rate with galaxy mass and between the size and the UV luminosity of our candidates. The analysis of the evolution of the UV luminosity function with redshift seems more compatible with an evolution of density. Moreover, no robust z>=8.5 object is selected behind the cluster field and few z~9 candidates have been selected in the two previous data sets from this legacy survey, suggesting a strong evolution in the number density of galaxies between z~8 and 9. Thanks to the use of the lensing cluster, we study the evolution of the star formation rate density produced by galaxies with L>0.03 L_{star}_, and confirm the strong decrease observed between z~8 and 9.
- ID:
- ivo://CDS.VizieR/J/MNRAS/468/305
- Title:
- Galaxy chemical evolution models
- Short Name:
- J/MNRAS/468/305
- Date:
- 19 Jan 2022 13:29:27
- Publisher:
- CDS
- Description:
- In our classical grid of multiphase chemical evolution models, star formation in the disc occurs in two steps: first, molecular gas forms, and then stars are created by cloud-cloud collisions or interactions of massive stars with the surrounding molecular clouds. The formation of both molecular clouds and stars are treated through the use of free parameters we refer to as efficiencies. In this work, we modify the formation of molecular clouds based on several new prescriptions existing in the literature, and we compare the results obtained for a chemical evolution model of the Milky Way Galaxy regarding the evolution of the Solar region, the radial structure of the Galactic disc and the ratio between the diffuse and molecular components, H I/H_2_. Our results show that the six prescriptions we have tested reproduce fairly consistent most of the observed trends, differing mostly in their predictions for the (poorly constrained) outskirts of the Milky Way and the evolution in time of its radial structure. Among them, the model proposed by Ascasibar et al. (in preparation), where the conversion of diffuse gas into molecular clouds depends on the local stellar and gas densities as well as on the gas metallicity, seems to provide the best overall match to the observed data.
- ID:
- ivo://CDS.VizieR/J/ApJS/246/2
- Title:
- Galaxy cluster cat. from SDSS-DR13 (GalWCat19)
- Short Name:
- J/ApJS/246/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Utilizing the SDSS-DR13 spectroscopic data set, we create a new publicly available catalog of 1800 galaxy clusters (GalWeight cluster catalog, GalWCat19) and a corresponding catalog of 34,471 identified member galaxies. The clusters are identified from overdensities in redshift phase space. The GalWeight technique introduced by Abdullah+ (2018ApJ...861...22A) is then applied to identify cluster members. The completeness of the cluster catalog (GalWCat19) and the procedure followed to determine cluster mass are tested on the Bolshoi N-body simulations. The 1800 GalWCat19 clusters range in redshift between 0.01 and 0.2 and have masses in the range of (0.4-14)x10^14^h^-1^M_{sun}_. The cluster catalog provides a large number of cluster parameters, including sky position, redshift, membership, velocity dispersion, and mass at overdensities {Delta}=500, 200, 100, and 5.5. The 34471 member galaxies are identified within the radius at which the density is 200 times the critical density of the universe. The galaxy catalog provides the coordinates of each galaxy and the ID of the cluster that the galaxy belongs to. The cluster velocity dispersion scales with mass as log({sigma}_200_)=log(946+/-52km/s)+ (0.349+/-0.142)log[h(z)M_200_/10^1 5^M_{sun}], with a scatter of {delta}log{sigma}=0.06+/-0.04.
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/892
- Title:
- Galaxy cluster concentration-mass relation
- Short Name:
- J/MNRAS/455/892
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Scaling relations of clusters have made them particularly important cosmological probes of structure formation. In this work, we present a comprehensive study of the relation between two profile observables, concentration (cvir) and mass (Mvir). We have collected the largest known sample of measurements from the literature which make use of one or more of the following reconstruction techniques: weak gravitational lensing (WL), strong gravitational lensing (SL), weak+strong lensing (WL+SL), the caustic method (CM), line-of-sight velocity dispersion (LOSVD), and X-ray. We find that the concentration-mass (c-M) relation is highly variable depending upon the reconstruction technique used. We also find concentrations derived from dark matter-only simulations (at approximately Mvir~10^14^M_{sun}_) to be inconsistent with the WL and WL+SL relations at the 1{sigma} level, even after the projection of triaxial haloes is taken into account. However, to fully determine consistency between simulations and observations, a volume-limited sample of clusters is required, as selection effects become increasingly more important in answering this. Interestingly, we also find evidence for a steeper WL+SL relation as compared to WL alone, a result which could perhaps be caused by the varying shape of cluster isodensities, though most likely reflects differences in selection effects caused by these two techniques. Lastly, we compare concentration and mass measurements of individual clusters made using more than one technique, highlighting the magnitude of the potential bias which could exist in such observational samples.
- ID:
- ivo://CDS.VizieR/J/AJ/141/88
- Title:
- Galaxy cluster environments of radio sources
- Short Name:
- J/AJ/141/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Sloan Digital Sky Survey (SDSS) and the Faint Images of the Radio Sky at Twenty Centimeters (FIRST) catalogs, we examined the optical environments around double-lobed radio sources. Previous studies have shown that multi-component radio sources exhibiting some degree of bending between components are likely to be found in galaxy clusters. Often this radio emission is associated with a cD-type galaxy at the center of a cluster. We cross-correlated the SDSS and FIRST catalogs and measured the richness of the cluster environments surrounding both bent and straight multi-component radio sources. This led to the discovery and classification of a large number of galaxy clusters out to a redshift of z~0.5.
- ID:
- ivo://CDS.VizieR/J/MNRAS/450/2261
- Title:
- Galaxy cluster outskirts probed by Chandra
- Short Name:
- J/MNRAS/450/2261
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We studied the physical properties of the intracluster medium (ICM) in the virialization region of a sample of 320 clusters (0.056<z<1.24, kT>~3keV) in the Chandra archive. With the emission measure profiles from this large sample, the typical gas density, gas slope and gas fraction can be constrained out to and beyond R200. We observe a steepening of the density profiles beyond R500 with {beta}~0.68 at R500 and {beta}~1 at R200 and beyond. By tracking the direction of the cosmic filaments approximately with the ICM eccentricity, we report that galaxy clusters deviate from spherical symmetry, with only small differences between relaxed and disturbed systems. We also did not find evolution of the gas density with redshift, confirming its self-similar evolution. The value of the baryon fraction reaches the cosmic value at R200; however, systematics due to non-thermal pressure support and clumpiness might enhance the measured gas fraction, leading to an actual deficit of the baryon budget with respect to the primordial value. This study has important implications for understanding the ICM physics in the outskirts.