- ID:
- ivo://CDS.VizieR/VII/89B
- Title:
- Compact groups of compact galaxies
- Short Name:
- VII/89B
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of ten published lists of compact groups of compact galaxies found on the Palomar Sky Survey red charts. The catalog contains 377 groups of compact galaxies and includes identifications, equatorial coordinates, numbers of constituent galaxies, magnitudes of the brightest member, sizes of the groups as a whole, and coefficients of relative compactness.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/426/296
- Title:
- Compact Groups of galaxies from 2MASX
- Short Name:
- J/MNRAS/426/296
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a photometric catalogue of compact groups of galaxies (p2MCGs) automatically extracted from the Two-Micron All Sky Survey (2MASS) extended source catalogue. A total of 262 p2MCGs are identified, following the criteria defined by Hickson, of which 230 survive visual inspection (given occasional galaxy fragmentation and blends in the 2MASS parent catalogue). Only one quarter of these 230 groups were previously known compact groups (CGs). Among the 144 p2MCGs that have all their galaxies with known redshifts, 85 (59%) have four or more accordant galaxies. This v2MCG sample of velocity-filtered p2MCGs constitutes the largest sample of CGs (with N>=4) catalogued to date, with both well-defined selection criteria and velocity filtering, and is the first CG sample selected by stellar mass. It is fairly complete up to K_group_~9 and radial velocity of ~6000km/s.
- ID:
- ivo://CDS.VizieR/J/AN/321/101
- Title:
- Compact groups of galaxies in LCRS
- Short Name:
- J/AN/321/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have recently extracted a catalog of compact groups of galaxies (CGs) from the Las Campanas Redshift Survey. This catalog of Las Campanas Compact Groups (LCCGs) contains 76 CGs with a median redshift of z_med_~0.08. The physical properties of these CGs are similar to those form Hickson (1982, Cat. <VII/213>) and the Barton et al. (1996AJ....112..871B) catalogs. Here, we present an atlas of our catalog and briefly describe its general properties.
- ID:
- ivo://CDS.VizieR/J/MNRAS/418/1409
- Title:
- Compact groups of galaxies in SDSS DR7
- Short Name:
- J/MNRAS/418/1409
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the properties of photometrically selected compact groups (CGs) in the Sloan Digital Sky Survey. In this paper, the fourth in a series, we focus on understanding the characteristics of our observed CG sample with particular attention paid to quantifying and removing contamination from projected foreground or background galaxies. Based on a simple comparison of pairwise redshift likelihoods, we find that approximately half of CGs in the parent sample contain one or more projected (interloping) members; our final clean sample contains 4566 galaxies in 1086 CGs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/395/255
- Title:
- Compact groups of galaxies in SDSS DR6
- Short Name:
- J/MNRAS/395/255
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the largest publicly available catalogue of compact groups (CGs) of galaxies identified using the original selection criteria of Hickson, selected from the Sixth Data Release of the Sloan Digital Sky Survey (SDSS DR6). We identify 2297 CGs down to a limiting magnitude of r=18 (~0.24groups/deg^2^), and 74791 CGs down to a limiting magnitude of r=21 (~6.7groups/deg^2^). This represents 0.9 per cent of all galaxies in the SDSS DR6 at these magnitude levels.
- ID:
- ivo://CDS.VizieR/J/MNRAS/382/1342
- Title:
- Compact stellar systems around NGC 1399
- Short Name:
- J/MNRAS/382/1342
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained spectroscopic redshifts of colour-selected point sources in four wide area VLT-FLAMES (Very Large Telescope-Fibre Large Array Multi Element Spectrograph) fields around the Fornax cluster giant elliptical galaxy NGC 1399, identifying as cluster members 27 previously unknown faint (-10.5<M_g'_<-8.8) compact stellar systems (CSS), and improving redshift accuracy for 23 previously catalogued CSS.
- ID:
- ivo://CDS.VizieR/J/ApJ/607/810
- Title:
- Companions to isolated elliptical galaxies
- Short Name:
- J/ApJ/607/810
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the number of physical companion galaxies for a sample of relatively isolated elliptical galaxies. The NASA/IPAC Extragalactic Database (NED) has been used to reinvestigate the incidence of satellite galaxies for a sample of 34 elliptical galaxies, first investigated by Bothun & Sullivan (1977PASP...89....5B) using a visual inspection of Palomar Sky Survey prints out to a projected search radius of 75 kpc. We have repeated their original investigation using data cataloged in NED. Nine of these elliptical galaxies appear to be members of galaxy clusters; the remaining sample of 25 galaxies reveals an average of +1.0+/-0.5 apparent companions per galaxy within a projected search radius of 75 kpc, in excess of two equal-area comparison regions displaced by 150-300 kpc. This is significantly larger than the +0.12+/-0.42 companions/galaxy found by Bothun & Sullivan (1977PASP...89....5B) for the identical sample. Making use of published radial velocities, mostly available since the completion of the Bothun-Sullivan study, identifies the physical companions and gives a somewhat lower estimate of +0.4 companions per elliptical galaxy. This is still 3 times larger than the original statistical study, but given the incomplete and heterogeneous nature of the survey redshifts in NED, it still yields a firm lower limit on the number (and identity) of physical companions. An expansion of the search radius out to 300 kpc, again restricted to sampling only those objects with known redshifts in NED, gives another lower limit of 4.5 physical companions per galaxy. (Excluding five elliptical galaxies in the Fornax Cluster, this average drops to 3.5 companions per elliptical.) These physical companions are individually identified and listed, and the ensemble-averaged radial density distribution of these associated galaxies is presented. For the ensemble, the radial density distribution is found to have a falloff consistent with {rho}{prop.to}R^-0.5^ out to approximately 150 kpc. For non-Fornax Cluster companions the falloff continues out to the 300 kpc limit of the survey. The velocity dispersion of these companions is found to reach a maximum of 350 km/s at around 120 kpc, after which they fall at a rate consistent with Keplerian falloff. This falloff may then indicate the detection of a cut-off in the mass-density distribution in the elliptical galaxies' dark matter halo at ~100 kpc.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/3738
- Title:
- Complete sample of galaxy clusters
- Short Name:
- J/MNRAS/469/3738
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The X-ray regime, where the most massive visible component of galaxy clusters, the intracluster medium, is visible, offers directly measured quantities, like the luminosity, and derived quantities, like the total mass, to characterize these objects. The aim of this project is to analyse a complete sample of galaxy clusters in detail and constrain cosmological parameters, like the matter density, {Omega}_m_, or the amplitude of initial density fluctuations, {sigma}_8_. The purely X-ray flux-limited sample (HIFLUGCS) consists of the 64 X-ray brightest galaxy clusters, which are excellent targets to study the systematic effects, that can bias results. We analysed in total 196 Chandra observations of the 64 HIFLUGCS clusters, with a total exposure time of 7.7Ms. Here, we present our data analysis procedure (including an automated substructure detection and an energy band optimization for surface brightness profile analysis) that gives individually determined, robust total mass estimates. These masses are tested against dynamical and Planck Sunyaev-Zeldovich (SZ) derived masses of the same clusters, where good overall agreement is found with the dynamical masses. The Planck SZ masses seem to show a mass-dependent bias to our hydrostatic masses; possible biases in this mass-mass comparison are discussed including the Planck selection function. Furthermore, we show the results for the (0.1-2.4)keV luminosity versus mass scaling relation. The overall slope of the sample (1.34) is in agreement with expectations and values from literature. Splitting the sample into galaxy groups and clusters reveals, even after a selection bias correction, that galaxy groups exhibit a significantly steeper slope (1.88) compared to clusters (1.06).
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/2614
- Title:
- Complex cluster Abell 1758 stars
- Short Name:
- J/MNRAS/466/2614
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a weak-lensing and dynamical study of the complex cluster Abell 1758 (A1758, {bar}z=0.278) supported by hydrodynamical simulations. This cluster is composed of two main structures called A1758N and A1758S. The northern structure is composed of A1758NW and A1758NE, with lensing determined masses of 7.90_-1.55_^+1.89^x10^14^M_{sun}_ and 5.49_-1.33_^+1.67^x10^14^M_{sun}_, respectively. They show a remarkable feature: while in A1758NW, there is a spatial agreement among weak-lensing mass distribution, intracluster medium and its brightest cluster galaxy (BCG), in A1758NE, the X-ray peak is located 96_-15_^+14^ arcsec away from the mass peak and BCG positions. Given the detachment between gas and mass, we could use the local surface mass density to estimate an upper limit for the dark matter self-interaction cross-section: {sigma}/m<5.83cm^2^/g. Combining our velocity data with hydrodynamical simulations, we have shown that A1758 NW and NE had their closest approach 0.27Gyr ago and their merger axis is 21+/-12{deg} from the plane of the sky. In the A1758S system, we have measured a total mass of 4.96_-1.19_^+1.08^x10^14^M_{sun}_ and, using radial velocity data, we found that the main merger axis is located at 70+/-4{deg} from the plane of the sky, therefore closest to the line of sight.
260. ComPRASS catalogue
- ID:
- ivo://CDS.VizieR/J/A+A/626/A7
- Title:
- ComPRASS catalogue
- Short Name:
- J/A+A/626/A7
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first all-sky catalogue of galaxy clusters and cluster candidates obtained from joint X-ray-SZ detections using observations from the Planck satellite and the ROSAT all-sky survey (RASS). The catalogue contains 2323 objects and has been validated by careful cross-identification with previously known clusters. This validation shows that 1597 candidates correspond to already known clusters, 212 coincide with other cluster candidates still to be confirmed, and the remaining 514 are completely new detections. With respect to Planck catalogues, the ComPRASS catalogue is simultaneously more pure and more complete. Based on the validation results in the SPT and SDSS footprints, the expected purity of the catalogue is at least 84.5%, meaning that more than 365 clusters are expected to be found among the new or still-to-be-confirmed candidates with future validation efforts or specific follow-ups.
