- ID:
- ivo://CDS.VizieR/J/A+A/479/927
- Title:
- Group of galaxies in SDSS 5
- Short Name:
- J/A+A/479/927
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We extract groups of galaxies from the SDSS Data Release 5 to study the supercluster-void network and environmental properties of groups therein. Groups of galaxies as density enhancements can be used to determine the luminosity density field of the supercluster-void network. We use a modified friends-of-friends (FoF) method with slightly variable linking lengths in transverse and radial directions to eliminate selection effects and to reliably find as many groups as possible. To determine the scaling of the linking length we calibrated group sizes and mean galaxy number densities within groups by shifting nearby groups to larger distances. Our final sample contains 17143 groups in the equatorial (E), and 33219 groups in the northern (N) part of the DR5 survey. The mean sizes and velocity dispersions of our groups practically do not change with their distance. This means that the selection effects have been properly taken into account when generating the group catalogue.
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Search Results
- ID:
- ivo://CDS.VizieR/VII/256
- Title:
- Groups of Galaxies from CfA2 Redshift Survey
- Short Name:
- VII/256
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains statistically homogeneous and physically well graunded groups of galaxies based on the CfA2 redshift survey (Cat. J/ApJS/121/287) in the area of space 1000km/s<=cz<=15000km/s, |bII|>=20{deg}. For identification of groups we used a modification of a friends of friends (FoF) method. Principles of friendship and definition of values of presented there free parameters described in Mahtessian (1988Afz....28..255M, 1997Ap.....40..285M). There are 1971 groups with 2 or more members, for a total of 6787 members (46.3%); 765 of the groups have 3 or more members with 4375 galaxies (28.1%). The others 8790 (56.4%) galaxies make a sample of "single" galaxies. The catalog includes group numbers, numbers of members, equatorial coordinates, Virgo-centric radial velocities, line-of-sight-velocity dispersions, integrated group luminosities, and relative quantity of false members.
- ID:
- ivo://CDS.VizieR/J/AJ/154/96
- Title:
- Groups of galaxies from from SDSS-DR7
- Short Name:
- J/AJ/154/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the dependence of stellar population properties of galaxies on group dynamical stage for a subsample of the Yang catalog. We classify groups according to their galaxy velocity distribution into Gaussian (G) and Non-Gaussian (NG). Using two totally independent approaches, we have shown that our measurement of Gaussianity is robust and reliable. Our sample covers Yang's groups in the redshift range 0.03{<=}z{<=}0.1, with mass {>=}10^14^M_{Sun}_. The new method, called Hellinger Distance, to determine whether a group has a velocity distribution Gaussian or NG is very effective in distinguishing between the two families. NG groups present halo masses higher than the G ones, confirming previous findings. Examining the skewness and kurtosis of the velocity distribution of G and NG groups, we find that faint galaxies in NG groups are mainly infalling, for the first time, into the groups. We show that considering only faint galaxies in the outskirts; those in NG groups are older and more metal-rich than those in G groups. Also, examining the Projected Phase Space of cluster galaxies, we see that bright and faint galactic systems in G groups are in dynamical equilibrium-which does not seem to be the case in NG groups. These findings suggest that NG systems have a higher infall rate, assembling more galaxies that have experienced preprocessing before entering the group.
- ID:
- ivo://CDS.VizieR/VII/84A
- Title:
- Groups of Galaxies. III. The CfA Survey
- Short Name:
- VII/84A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains statistically homogeneous groups of galaxies based on the Harvard-Smithsonian Center for Astrophysics (CfA) redshift survey. Groups in the catalog are all density enhancements in redshift space of a factor greater than 20. All groups contain at least three members. There are 176 groups in the catalog and 102 groups have been identified in one or more previous studies. The catalog includes group numbers, numbers of members, equatorial coordinates, mean flow-corrected galactocentric velocities, line-of-sight-velocity dispersion, integrated group magnitudes, crossing times for the groups, and mean harmonic radii of the groups.
- ID:
- ivo://CDS.VizieR/VII/86A
- Title:
- Groups of Galaxies. I. Nearby Groups
- Short Name:
- VII/86A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains nearby groups of galaxies with outer number density enhancement greater than 20. The groups were searched using a whole sky catalog of 1312 galaxies brighter than mag 13.2 (B) with complete redshift information (Huchra et al. =1983ApJS...52...89H). Only groups containing more than two members are included. The catalogue includes equatorial coordinates, average radial velocities, and velocity dispersions for 92 nearby groups in the first file. A second file contains the results of a comparison between this catalog and de Vaucouleurs' (1975) catalog of nearby groups The Hubble constant was assumed 100km/s/Mpc.
- ID:
- ivo://CDS.VizieR/J/ApJ/655/790
- Title:
- Groups of galaxies in 2MASS survey
- Short Name:
- J/ApJ/655/790
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of applying a percolation algorithm to the initial release of the Two Micron All Sky Survey Extended Source Catalog, using subsequently measured redshifts for almost all of the galaxies with K<11.25mag. This group catalog is based on the first near-IR all-sky flux-limited survey that is complete to |b|=5{deg}. We explore the dependence of the clustering on the length and velocity scales involved. The paper describes a group catalog, complete to a limiting redshift of 104km/s, created by maximizing the number of groups containing three or more members. A second catalog is also presented, created by requiring a minimum density contrast of {delta}{rho}/{rho}>=80 to identify groups. We identify known nearby clusters in the catalogs and contrast the groups identified in the two catalogs. We examine and compare the properties of the determined groups and verify that the results are consistent with the UZC-SSRS2 and northern CfA redshift survey group catalogs. The all-sky nature of the catalog will allow the development of a flow-field model based on the density field inferred from the estimated cluster masses.
- ID:
- ivo://CDS.VizieR/J/A+AS/103/245
- Title:
- Gunn gri photometry of Clusters of Galaxies
- Short Name:
- J/A+AS/103/245
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+AS/119/391
- Title:
- Gunn photometry of seven clusters of galaxies
- Short Name:
- J/A+AS/119/391
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gunn g, r, i photometry for the 7 clusters MRC0254-274, Cl0317+15, MS0418.3-3 844, Cl1141-283, A1689, A3594, S0781B is presented. For each cluster we derived the spatial distribution properties obtaining the core radius and the concentration parameters. Color properties of the cluster galaxy population are also briefly discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/569/A124
- Title:
- GUViCS. Ultraviolet Source Catalogs
- Short Name:
- J/A+A/569/A124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we introduce the deepest and most extensive ultraviolet extragalactic source catalogs of the Virgo Cluster area to date. Archival and targeted GALEX imaging is compiled and combined to provide the deepest possible coverage over ~120deg^2^ in the NUV (lambda_eff_=2316{AA}) and ~40deg^2^ in the FUV (lambda_eff_=1539{AA}) between 180{deg}<=RA<=195{deg} and 0{deg}<=DE<=20{deg}. We measure the integrated photometry of 1770 extended UV sources of all galaxy types and use GALEX pipeline photometry for 1,230,855 point-like sources in the foreground, within, and behind the cluster. Extended source magnitudes are reliable to m_UV_~22, showing a ~0.01{sigma} difference from their asymptotic magnitudes. Point-like source magnitudes have a 1{sigma} standard deviation within ~0.2mag down to m_uv_~23. The point-like source catalog is cross-matched with large optical databases and surveys including the SDSS DR9 (>1 million Virgo Cluster sources), the Next Generation Virgo Cluster Survey (NGVS; >13 million Virgo Cluster sources), and the NED (~30,000 sources in the Virgo Cluster). We find that 69% of the entire UV point-like source catalog has a unique optical counterpart, 11% of which are stars and 0.01% (129) are Virgo cluster members that are neither in the VCC nor part of the bright CGCG galaxy catalog (i.e., m_pg_<14.5). These data are collected in three catalogs containing the UV extended sources, the UV point-like sources, and the most relevant optical parameters of UV-optically matched point-like sources for further studies from SDSS. The GUViCS catalogs provide a unique set of data for future work on UV and multiwavelength studies in the cluster and background environments.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A16
- Title:
- Halpha3. Catalog and SFR in Virgo cluster
- Short Name:
- J/A+A/545/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present H{alpha}3 (acronym for H{alpha}-{alpha}{alpha}), an H{alpha} narrow-band imaging survey of ~400 galaxies selected from the HI Arecibo Legacy Fast ALFA Survey (ALFALFA) in the Local Supercluster, including the Virgo cluster. By using hydrogen recombination lines as a tracer of recent star formation, we aim to investigate the relationships between atomic neutral gas and newly formed stars in different environments (cluster and field), morphological types (spirals and dwarfs), and over a wide range of stellar masses (~10^7.5^-10^11.5^M_{sun}_). We image in H{alpha}+[NII] all the galaxies that contain more than 10^7^M_{sun}_ of neutral atomic hydrogen in the sky region 11h<R.A.<16h ; 4{deg}<Dec.<16{deg}; 350<cz<2000km/s using the San Pedro Martir 2m telescope. This survey provides a complete census of the star formation in HI rich galaxies of the local universe. We present the properties of the galaxy sample, together with H{alpha} fluxes and equivalent widths. We find an excellent agreement between the fluxes determined from our images in apertures of 3-arcsec diameter and the fluxes derived from the SDSS spectral database. From the H{alpha} fluxes corrected for galactic and internal extinction and for [NII] contamination we derive the global star formation rates (SFRs).
