Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/382/389
- Title:
- CCD R photometry of 17 clusters of galaxies
- Short Name:
- J/A+A/382/389
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a study of streaming motion of galaxy clusters around the Giant Void (RA~13h, DE~40{deg}, z~0.11 and a diameter of 150/hMpc) in the distribution of rich Abell clusters. We used the Kormendy relation as a distance indicator taking into account galaxy luminosities. Observations were carried out in Kron-Cousins R_c_ system on the 6m and 1m telescopes of SAO RAS. For 17 clusters in a spherical shell of 25/hMpc in thickness centered on the void no significant diverging motion (expected to be generated by the mass deficit in the void) has been detected. This implies that cosmological models with low {Omega}_m_ are preferred. To explain small mass underdensity inside the Giant Void, a mechanism of void formation with strong biasing is required.
- ID:
- ivo://CDS.VizieR/J/MNRAS/497/1791
- Title:
- CCD Washington photometry of Antlia cluster
- Short Name:
- J/MNRAS/497/1791
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an extension of our previous research on the early-type galaxy population of the Antlia cluster (d~35Mpc), achieving a total coverage of ~2.6deg^2^ and performing surface photometry for ~300 galaxies, 130 of which are new uncatalogued ones. Such new galaxies mainly fall in the low surface brightness (LSB) regime, but there are also some lenticulars (S0) which support the existence of unique functions that connect bright and dwarf galaxies in the scaling relations. We analyse the projected spatial distribution of galaxies up to a distance of ~800kpc from NGC 3268, the adopted centre, as well as the radial velocity distribution and the correlation between galaxy colour and effective radius with the projected spatial distribution. We also obtain the luminosity function of the early-type galaxies and the distribution of stellar masses using the T1-band magnitudes and adopted mass-luminosity ratios. Additionally, we correlate the central galaxy distribution with an X-ray emission map from the literature. Based on the analysis of the radial velocities and galaxy colour distributions, we find that galaxies redder than the colour-magnitude relation (CMR) have a velocity distribution strongly concentrated towards the values of the dominant galaxies and are homogeneously distributed throughout the cluster. Those bluer than the CMR, in turn, have a much more extended radial velocity distribution and are concentrated towards the centre of the cluster. We also identify 12 candidates to ultra diffuse galaxies (UDG), that seem to be split into two families, and speculate about their origins in the context of the cluster structure.
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/2948
- Title:
- Ccompact group galaxies UV and IR SFR
- Short Name:
- J/MNRAS/459/2948
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Compact groups of galaxies provide insight into the role of low-mass, dense environments in galaxy evolution because the low velocity dispersions and close proximity of galaxy members result in frequent interactions that take place over extended time-scales. We expand the census of star formation in compact group galaxies by Tzanavaris et al. (2010, Cat. J/ApJS/212/9) and collaborators with Swift UVOT, Spitzer IRAC and MIPS 24{mu}m photometry of a sample of 183 galaxies in 46 compact groups. After correcting luminosities for the contribution from old stellar populations, we estimate the dust-unobscured star formation rate (SFR_UV_) using the UVOT uvw2 photometry. Similarly, we use the MIPS 24 {mu}m photometry to estimate the component of the SFR that is obscured by dust (SFR_IR_). We find that galaxies which are MIR-active (MIR-'red'), also have bluer UV colours, higher specific SFRs, and tend to lie in HI-rich groups, while galaxies that are MIR-inactive (MIR-'blue') have redder UV colours, lower specific SFRs, and tend to lie in HI-poor groups. We find the SFRs to be continuously distributed with a peak at about 1M_{sun}_/yr, indicating this might be the most common value in compact groups. In contrast, the specific SFR distribution is bimodal, and there is a clear distinction between star-forming and quiescent galaxies. Overall, our results suggest that the specific SFR is the best tracer of gas depletion and galaxy evolution in compact groups.
- ID:
- ivo://CDS.VizieR/J/ApJ/833/15
- Title:
- CCPC. II. 2<z<6.6 protocluster candidates
- Short Name:
- J/ApJ/833/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Candidate Cluster and Protocluster Catalog (CCPC) is a list of objects at redshifts z>2 composed of galaxies with spectroscopically confirmed redshifts that are coincident on the sky and in redshift. These protoclusters are identified by searching for groups in volumes corresponding to the expected size of the most massive protoclusters at these redshifts. In CCPC1 we identified 43 candidate protoclusters among 14000 galaxies between 2.74<z<3.71. Here we expand our search to more than 40000 galaxies with spectroscopic redshifts z>2.00, resulting in an additional 173 candidate structures. The most significant of these are 36 protoclusters with overdensities {delta}_gal_>7. We also identify three large proto-supercluster candidates containing multiple protoclusters at z=2.3, 3.5 and z=6.56. Eight candidates with N>=10 galaxies are found at redshifts z>4.0. The last system in the catalog is the most distant spectroscopic protocluster candidate known to date at z=6.56.
- ID:
- ivo://CDS.VizieR/J/AJ/106/831
- Title:
- cD clusters of galaxies. I.
- Short Name:
- J/AJ/106/831
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the initial results of a spectroscopic study of a sample of cD galaxy clusters. The goal of this program is to study the dynamics of the clusters, with emphasis on determining the nature and frequency of peculiar velocity cD galaxies. In this paper we present redshifts for 611 galaxies in the fields of the rich Abell clusters A193, A399, A401, A1795, A1809, A2063, and A2124. We discuss our data reduction techniques, and compare our derived velocities with previously published values. We find a frequency of emission line galaxies of ~6% in clusters, a factor of 2-3 less than the field.
- ID:
- ivo://CDS.VizieR/J/AJ/116/1529
- Title:
- cD clusters of galaxies. III.
- Short Name:
- J/AJ/116/1529
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the final observational data for a spectroscopic study of a sample of cD galaxy clusters. The goal of this program has been to study the dynamics of the clusters, with emphasis on determining the nature and frequency of peculiar-velocity cD galaxies. In this paper we present redshifts for 762 galaxies in the fields of the rich Abell clusters A779, A1691, A1749, A1767, A1837, A1927, A2067, A2079, A2089, A2199, and A2666. We also present preliminary dynamical properties for these clusters using our measured redshifts.
- ID:
- ivo://CDS.VizieR/J/AJ/104/2078
- Title:
- cD Galaxy in Abell 2107
- Short Name:
- J/AJ/104/2078
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of a program to study the kinematics of cD clusters of galaxies, we have measured the radial velocities of 75 galaxies in the field of Abell 2107. Sixty-eight of these galaxies are cluster members. The mean observed velocity of A2105 is 12335 +/- 86 km/s and the velocity dispersion is 672 [+67,-52] km/s. The cD galaxy has a peculiar velocity of 270 km/s with respect to the cluster mean. The distribution of velocities is well fitted by a Gaussian, but the velocities are spatially correlated. We have investigated simple two-body subcluster models for A2107, which are consistent with the observed data and account for the peculiar velocity of the cD galaxy. Alternatively, the spatial distribution of velocities is also consistent with rotation of a single cluster at the 98% confidence level. However, the pure rotation model fails to explain the peculiar velocity of the cD galaxy, which lies at the center of the cluster.
- ID:
- ivo://CDS.VizieR/VII/88
- Title:
- CEDAG Catalogue of Clusters of Galaxies
- Short Name:
- VII/88
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains for 10411 objects, the Abell, Zwicky, and Kalinkov numbers of groups of galaxies. In addition, it contains: Abell or Zwicky coordinates, the Abell or Zwicky numbers of the supercluster which contains each group, the diameter (Zwicky), the magnitude (Abell), the compactness (Zwicky), the distance of the group (both Abell and Zwicky), the richness (Abell) and the population (Zwicky).
- ID:
- ivo://CDS.VizieR/J/ApJS/170/95
- Title:
- Centaurus Cluster catalog
- Short Name:
- J/ApJS/170/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of all galaxies with V<=22.0 and R_iso_>3" within a 0.83deg^2^ region centered on the Centaurus Cluster (Abell 3526) at RA=12h48m, DE=-41{deg}18'. V-band total magnitudes along with other photometric parameters were obtained from the detection programs FOCAS and SExtractor and also from fitting curve-of-growth Sersic functions to the galaxy profiles. Central surface brightnesses, half-light radii, ellipticity, and position angles are presented, along with (B-V) aperture colors where B-band data were obtained. This work is part of a larger program to study the cluster-to-cluster variation in the faint end of the LF based on the study of eight clusters, including Centaurus. We discuss our data reduction methods in this paper. More detailed analyses and science results will be presented in subsequent papers.
