- ID:
- ivo://CDS.VizieR/J/ApJ/384/404
- Title:
- Redshifts of a nearby rich clusters of galaxies
- Short Name:
- J/ApJ/384/404
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Abstract of the paper) We have acquired redshifts for a complete sample of 351 Abell clusters with tenth-ranked galaxy magnitudes (m_10_) less than or equal to 16.5, including 115 entirely new cluster redshifts. The survey includes all such clusters which lie north of {delta}=-27deg30arcmin and is the largest magnitude-limited redshift survey of rich clusters to date. Analysis of the spatial distribution of these clusters reveals no clustering on scales larger than 75h^-1^Mpc; we do not detect the large supercluster complexes reported by Tully. The correlation length is 20.0(+/-4.3)h^-1^Mpc, consistent with the results from other surveys. The frequency of voids with radii of order 60h^-1^Mpc or less is consistent with the form and amplitude of the observed two-point correlation function. There is no significant difference between the clustering properties of RC = O and RC >= 1 clusters. A percolation analysis yields 23 superclusters, 17 of which are new. The superclusters are not significantly elongated in the radial direction; large-scale peculiar motions are of order 1000 km s^-1^ or less. Dramatically new constraints on the large-scale cluster distribution will require surveys an order of magnitude larger.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/365/66
- Title:
- Redshifts of a sample of distant Abell clusters
- Short Name:
- J/ApJ/365/66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured redshifts for a complete sample of 145 Abell clusters of galaxies. The sample covers a 561 square degree region at high Galactic latitude. The median redshift of the clusters in the sample is 0.16. For R >= 1 clusters the correlation length is r_0_ = 21 h^-1^ Mpc. The amplitude of the correlation function is a factor of 1.4 less than that obtained by Bahcall and Soneira, but the difference is within the 1 {sigma} uncertainties. In this sample we cannot detect clustering on scales >~ 70 h^-1^ Mpc. Although the maps of the cluster distribution in redshift space show a large void of diameter ~20,000 km s^-1^, frequent occurrence of such large empty regions is consistent with the smaller scale behaviour of the correlation function of the survey. Large-scale peculiar motions are <~1000 km s^-1^. This limit is inconsistent with the claim of detection by Bahcall, Soneira, and Burgett of ~2000 km/s peculiar motions. We suggest that the earlier result is affected by the Corona Borealis supercluster, which contributes more than a third of the excess pairs in the shallower survey.
- ID:
- ivo://CDS.VizieR/J/AJ/123/100
- Title:
- Redshifts of AWM and MKW poor clusters
- Short Name:
- J/AJ/123/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured 1365 redshifts to a limiting magnitude of R~15.5 in 15 AWM/MKW clusters and have collected another 203 from the literature in MKW 4s, MKW 2, and MKW 2s. In AWM 7 we have extended the redshift sample to R~18 in the cluster center. We have identified 704 cluster members in 17 clusters; 201 are newly identified. We summarize the kinematics and distributions of the cluster galaxies and provide an initial discussion of substructure, mass and luminosity segregation, spectral segregation, velocity-dispersion profiles, and the relation of the central galaxy to global cluster properties. We compute optical mass estimates, which we compare with X-ray mass determinations from the literature.
- ID:
- ivo://CDS.VizieR/J/A+A/427/397
- Title:
- Redshifts of 5 EDisCS galaxy clusters
- Short Name:
- J/A+A/427/397
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spectroscopic observations are presented for objects in the fields of 4 galaxy clusters at z=0.7-0.8 (Cl 1040.7-1155 (Cl 1040), Cl 1054.4-1146 (Cl 1054-11), Cl 1054.7-1245 (Cl 1054-12), and Cl 1216.8-1201 (Cl 1216)) and in one cluster at z~0.5 (Cl 1232.5-1250 (Cl 1232)) of the ESO Distant Cluster Survey (EDisCS). We present tables of RA and DE positions for an equinox of 2000 (J2000, epoch 2001), I-band magnitudes for an aperture of radius 1 arcsecond, spectroscopic redshifts for objects in the fields of our 5 clusters, and membership and targeting flags to indicate whether the object is a cluster member and/or was targeted to be a cluster member respectively.
- ID:
- ivo://CDS.VizieR/J/A+A/409/439
- Title:
- Redshifts of 11 EIS clusters
- Short Name:
- J/A+A/409/439
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of carrying out multi-object spectroscopy in 10 EIS cluster fields. Based on the list of 345 galaxy redshifts we identify significant 3D-density enhancements. For 9 of the EIS clusters we identify significant 3D-concentrations corresponding to the originally detected cluster candidate. We find redshifts in the range 0.097<=z<=0.257 which is in good agreement with the matched filter estimate of z_MF_=0.2. We estimate velocity dispersions in the range 219-1160km/s for the confirmed clusters
- ID:
- ivo://CDS.VizieR/J/A+A/388/1
- Title:
- Redshifts of five EIS clusters
- Short Name:
- J/A+A/388/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of the first multi-object spectroscopic observations at the Danish 1.54m telescope at La Silla, Chile. Observations of five cluster candidates from The ESO Imaging Survey Cluster Candidate Catalog are described. From these observations we confirm the reality of the five clusters with measured redshifts of 0.11<=z<=0.35. We estimate velocity dispersions in the range 294-621km/s indicating rather poor clusters. This, and the measured cluster redshifts are consistent with the results of the matched filter procedure applied to produce the Cluster Candidate Catalog.
- ID:
- ivo://CDS.VizieR/J/ApJ/781/2
- Title:
- Redshifts of 1151 galaxies from SDSS
- Short Name:
- J/ApJ/781/2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Lines of sight with multiple projected cluster-scale gravitational lenses have high total masses and complex lens plane interactions that can boost the area of magnification, or etendue, making detection of faint background sources more likely than elsewhere. To identify these new "compound" cosmic telescopes, we have found directions in the sky with the highest integrated mass densities, as traced by the projected concentrations of luminous red galaxies (LRGs). We use new galaxy spectroscopy to derive preliminary magnification maps for two such lines of sight with total mass exceeding ~3x10^15^M_{sun}_. From 1151 MMT Hectospec spectra of galaxies down to i_AB_=21.2, we identify two to three group- and cluster-scale halos in each beam. These are well traced by LRGs. The majority of the mass in beam J085007.6+360428 (0850) is contributed by Zwicky 1953, a massive cluster at z=0.3774, whereas beam J130657.5+463219 (1306) is composed of three halos with virial masses of 6x10^14^-2x10^15^M_{sun}_, one of which is A1682. The magnification maps derived from our mass models based on spectroscopy and Sloan Digital Sky Survey photometry alone display substantial etendue: the 68% confidence bands on the lens plane area with magnification exceeding 10 for a source plane of z_s_=10 are [1.2,3.8]arcmin^2^ for 0850 and [2.3,6.7]arcmin^2^ for 1306. In deep Subaru Suprime-Cam imaging of beam 0850, we serendipitously discover a candidate multiply imaged V-dropout source at z_phot_=5.03. The location of the candidate multiply imaged arcs is consistent with the critical curves for a source plane of z=5.03 predicted by our mass model. Incorporating the position of the candidate multiply imaged galaxy as a constraint on the critical curve location in 0850 narrows the 68% confidence band on the lens plane area with {mu}>10 and z_s_=10 to [1.8,4.2]arcmin^2^, an etendue range comparable to that of MACS 0717+3745 and El Gordo, two of the most powerful single cluster lenses known. The significant lensing power of our beams makes them powerful probes of reionization and galaxy formation in the early universe.
- ID:
- ivo://CDS.VizieR/J/MNRAS/442/2216
- Title:
- Redshifts of galaxies in Abell 1351 field
- Short Name:
- J/MNRAS/442/2216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to review the internal structure and dynamics of the Abell 1351 cluster, shown to host a radio halo with a quite irregular shape. Our analysis is based on radial velocity data for 135 galaxies obtained at the Telescopio Nazionale Galileo. We combine galaxy velocities and positions to select 95 cluster galaxy members and analyse the internal dynamics of the whole cluster. We also examine X-ray data retrieved from Chandra and XMM archives. We measure the cluster redshift, <z>=0.325, the line-of-sight (LOS) velocity dispersion, {sigma}V~1500km/s, and the X-ray temperature, kT~9keV. From both X-ray and optical data independently, we estimate a large cluster mass, in the 1-4x10^15^h_70_^-1^M_{sun}_. We attribute the extremely high value of {sigma}V to the bimodality in the velocity distribution. We find evidence of a significant velocity gradient and optical 3D substructure. The X-ray analysis also shows many features in favour of a complex cluster structure, probably supporting an ongoing merger of substructures in Abell 1351. The observational scenario agrees with the presence of two main subclusters in the northern region, each with its brightest galaxy (BCG1 and BCG2), detected as the two most important X-ray substructures with a rest-frame LOS velocity difference of {Delta}V_rf_~2500km/s and probably being in large part aligned with the LOS. We conclude that Abell 1351 is a massive merging cluster. The details of the cluster structure allow us to interpret the quite asymmetric radio halo as a 'normal' halo plus a southern relic, strongly supporting a previous suggestion based only on inspection of radio and preliminary X-ray data.
- ID:
- ivo://CDS.VizieR/J/A+A/425/429
- Title:
- Redshifts of 119 galaxies in ACO 1367
- Short Name:
- J/A+A/425/429
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Redshifts of 119 galaxies in the Abell cluster 1367 are presented. The majority (98) were obtained with the AF2-WYFFOS multi fiber spectrograph at the 4.2m William Herschel Telescope (WHT). Nine additional long-slit, low dispersion spectra were obtained using the imaging spectrograph BFOSC attached to the Cassini 1.5m telescope at Loiano. Another twelve spectra were taken with LFOSC at the 2.1m telescope of the Guillermo Haro Observatory at Cananea.
- ID:
- ivo://CDS.VizieR/J/A+A/435/781
- Title:
- Redshifts of galaxies in 21 EIS cluster fields
- Short Name:
- J/A+A/435/781
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out an investigation of the properties of low redshift EIS clusters using both spectroscopy and imaging data. We present new redshifts for 738 galaxies in 21 ESO Imaging Survey (EIS) Cluster fields. We use the "gap"-technique to search for significant overdensities in redshift space and to identify groups/clusters of galaxies corresponding to the original EIS matched filter cluster candidates. In this way we spectroscopically confirm 20 of the 21 cluster candidates with a matched-filter estimated redshift z_MF_=0.2. We have now obtained spectroscopic redshifts for 34 EIS cluster candidates with z_MF_=0.2 (see also Hansen et al., 2002, Cat. <J/A+A/388/1>; Olsen et al., 2003, Cat. <J/A+A/409/439>. Of those we spectroscopically confirm 32 with redshifts ranging from z=0.064 to 0.283. We find that: 1) the velocity dispersions of the systems range from sigma_v_<=130km/s to sigma_v_=1200km/s, typical of galaxy groups to rich clusters; 2) richnesses corresponding to Abell classes R<=1; and 3) concentration indices ranging from C=0.2 to C=1.2. From the analysis of the colours of the galaxy populations we find that 53% of the spectroscopically confirmed systems have a "significant" red sequence. These systems are on average richer and have higher velocity dispersions. We find that the colour of the red sequence galaxies matches passive stellar evolution predictions.
