- ID:
- ivo://CDS.VizieR/J/A+A/461/81
- Title:
- Galaxy clusters in the CFHTLS
- Short Name:
- J/A+A/461/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We apply a matched-filter cluster detection algorithm to the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS) i-band data for the Deep-1, Deep-2, Deep-3 and Deep-4 fields covering a total of 4 square degrees. To test the implemented procedure we carry out simulations for assessing the frequency of noise peaks as well as estimate the recovery efficiency. We estimate that up to z~0.7 the catalogue is essentially complete for clusters of richness class R>~1. The recovered redshifts are in general overestimated by dz=0.1 with a scatter of sigma_dz_~0.1, except at redshifts z>~1 where the estimated redshifts are systematically underestimated. The constructed cluster candidate catalogue contains 162 detections over an effective area of 3.112 square degrees corresponding to a density of ~52.1 per square degree. The median estimated redshift of the candidates is z=0.6. The estimated noise frequency is 16.9+/-5.4 detections per square degree. From visual inspection we identify systems that show a clear concentration of galaxies with similar colour. These systems have a density of ~20 per square degree.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/535/A65
- Title:
- Galaxy clusters in the 4 CFHTLS Wide fields
- Short Name:
- J/A+A/535/A65
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have developed a method for detecting clusters in large imaging surveys, based on the detection of structures in galaxy density maps made in slices of photometric redshifts. This method was first applied to the Canada France Hawaii Telescope Legacy Survey (CFHTLS) Deep 1 field by Mazure et al. (2007A&A...467...49M), then to all the Deep and Wide CFHTLS fields available in the T0004 data release by Adami et al. (2010, Cat. J/A+A/509/81). The validity of the cluster detection rate was estimated by applying the same procedure to galaxies from the Millennium simulation. Here we analyse with the same method the full CFHTLS Wide survey, based on the T0006 data release. In a total area of 154deg^2^, we have detected 4061 candidate clusters at 3sigma or above (6802 at 2sigma and above), in the redshift range 0.1<=z<=1.15, with estimated mean masses between 1.3x10^14^ and 12.6x10^14^M_{sun}_. We compare our detections with those made in various CFHTLS analyses with other methods. By stacking a subsample of clusters, we show that this subsample has typical cluster characteristics (colour-magnitude relation, galaxy luminosity function). We also confirm that the cluster-cluster correlation function is comparable to that obtained for other cluster surveys and analyze large scale filamentary galaxy distributions. We have increased the number of known optical high redshift cluster candidates by a large factor, an important step towards obtaining reliable cluster counts to measure cosmological parameters. The clusters that we detect behave as expected for a sample of clusters fed by filaments at the intersection of which they are located.
- ID:
- ivo://CDS.VizieR/J/ApJ/736/21
- Title:
- Galaxy clusters optical catalog from AMF on SDSS DR6
- Short Name:
- J/ApJ/736/21
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a new cluster catalog extracted from the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) using an adaptive matched filter (AMF) cluster finder. We identify 69,173 galaxy clusters in the redshift range 0.045<=z<0.78 in 8420deg^2^ of the sky. We provide angular position, redshift, richness, core, and virial radii estimates for these clusters, as well as an error analysis for each of these quantities. We also provide a catalog of more than 205,000 galaxies representing the three brightest galaxies in the r band which are possible brightest cluster galaxy (BCG) candidates. We show basic properties of the BCG candidates and study how their luminosity scales in redshift and cluster richness. We compare our catalog with the maxBCG and GMBCG catalogs, as well as with that of Wen et al. We match between 30% and 50% of clusters between catalogs over all overlapping redshift ranges. We find that the percentage of matches increases with the richness for all catalogs. We cross match the AMF catalog with available X-ray data in the same area of the sky and find 539 matches, 119 of which with temperature measurements. We present scaling relations between optical and X-ray properties and cluster center comparison.
- ID:
- ivo://CDS.VizieR/J/ApJ/748/15
- Title:
- Galaxy distances with the Fundamental Manifold
- Short Name:
- J/ApJ/748/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We demonstrate how the Fundamental Manifold (FM) can be used to cross-calibrate distance estimators even when those "standard candles" are not found in the same galaxy. Such an approach greatly increases the number of distance measurements that can be utilized to check for systematic distance errors and the types of estimators that can be compared. Here we compare distances obtained using Type Ia supernova (SN Ia), Cepheids, surface brightness fluctuations, the luminosity of the tip of the red giant branch, circumnuclear masers, eclipsing binaries, RR Lyrae stars, and the planetary nebulae luminosity functions. We find no significant discrepancies (differences are <2{sigma}) between distance methods, although differences at the ~10% level cannot yet be ruled out. The potential exists for significant refinement because the data used here are heterogeneous B-band magnitudes that will soon be supplanted by homogeneous, near-infrared magnitudes. We illustrate the use of FM distances to (1) revisit the question of the metallicity sensitivity of various estimators, confirming the dependence of SN Ia distances on host galaxy metallicity, and (2) provide an alternative calibration of H_0_ that replaces the classical ladder approach in the use of extragalactic distance estimators with one that utilizes data over a wide range of distances simultaneously.
- ID:
- ivo://CDS.VizieR/J/ApJ/552/427
- Title:
- Galaxy groups a intermediate redshifts
- Short Name:
- J/ApJ/552/427
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxy groups likely to be virialized are identified within the CNOC2, (Yee et al., 2000, Cat. <J/ApJS/129/475>) intermediate-redshift galaxy survey. The resulting groups have a median velocity dispersion, {sigma}1=~200km/s. The virial mass-to-light ratios, using k-corrected and evolution-compensated luminosities, have medians in the range of 150-250h M_{suns}_/L_{sun}_, depending on group definition details. The number-velocity dispersion relation at {sigma}1>~200km/s is in agreement with the low-mass extrapolation of the cluster-normalized Press-Schechter model. Lower velocity dispersion groups are deficient relative to the Press-Schechter model. The two-point group-group autocorrelation function has r0=6.8+/-0.3h^-1^Mpc, which is much larger than the correlations of individual galaxies, but about as expected from biased clustering. The mean number density of galaxies around group centers falls nearly as a power law with r^-2.5^ and has no well-defined core. The projected velocity dispersion of galaxies around group centers is either flat or slowly rising outward. The combination of a steeper than isothermal density profile and the outward rising velocity dispersion implies that the mass-to-light ratio of groups rises with radius if the velocity ellipsoid is isotropic but could be nearly constant if the galaxy orbits are nearly circular. Such strong tangential anisotropy is not supported by other evidence. Although the implication of a rising M/L must be viewed with caution, it could naturally arise through dynamical friction acting on the galaxies in a background of "classical" collisionless dark matter.
- ID:
- ivo://CDS.VizieR/J/ApJS/167/1
- Title:
- Galaxy groups and clusters from SDSS
- Short Name:
- J/ApJS/167/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify galaxy groups and clusters in volume-limited samples of the Sloan Digital Sky Survey (SDSS) redshift survey, using a redshift-space friends-of-friends algorithm. We optimize the friends-of-friends linking lengths to recover galaxy systems that occupy the same dark matter halos, using a set of mock catalogs created by populating halos of N-body simulations with galaxies. Extensive tests with these mock catalogs show that no combination of perpendicular and line-of-sight linking lengths is able to yield groups and clusters that simultaneously recover the true halo multiplicity function, projected size distribution, and velocity dispersion. We adopt a linking length combination that yields, for galaxy groups with 10 or more members: a group multiplicity function that is unbiased with respect to the true halo multiplicity function; an unbiased median relation between the multiplicities of groups and their associated halos; a spurious group fraction of less than ~1%; a halo completeness of more than 97%; the correct projected size distribution as a function of multiplicity; and a velocity dispersion distribution that is ~20% too low at all multiplicities. These results hold over a range of mock catalogs that use different input recipes of populating halos with galaxies. We apply our group-finding algorithm to the SDSS data and obtain three group and cluster catalogs for three volume-limited samples that cover 3495.1deg^2^ on the sky, go out to redshifts of 0.1, 0.068, and 0.045, and contain 57138, 37820, and 18895 galaxies, respectively. We correct for incompleteness caused by fiber collisions and survey edges and obtain measurements of the group multiplicity function, with errors calculated from realistic mock catalogs. These multiplicity function measurements provide a key constraint on the relation between galaxy populations and dark matter halos.
- ID:
- ivo://CDS.VizieR/J/ApJ/625/6
- Title:
- Galaxy groups in the DEEP2 Galaxy Redshift Survey
- Short Name:
- J/ApJ/625/6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic data to identify groups and clusters of galaxies in redshift space. The data set contains 8370 galaxies with confirmed redshifts in the range 0.7<=z<=1.4, over 1{deg}^2^ on the sky. Groups are identified using an algorithm (the Voronoi-Delaunay method) that has been shown to accurately reproduce the statistics of groups in simulated DEEP2-like samples. We optimize this algorithm for the DEEP2 survey by applying it to realistic mock galaxy catalogs and assessing the results using a stringent set of criteria for measuring group-finding success, which we develop and describe in detail here. We present the first DEEP2 group catalog, which assigns 32% of the galaxies to 899 distinct groups with two or more members, 153 of which have velocity dispersions above 350km/s. We provide locations, redshifts and properties for this high-dispersion subsample. This catalog represents the largest sample to date of spectroscopically detected groups at z~1.
- ID:
- ivo://CDS.VizieR/J/A+A/520/A42
- Title:
- Galaxy groups in the VIMOS-VLT Deep Survey
- Short Name:
- J/A+A/520/A42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a homogeneous and complete catalogue of optical galaxy groups identified in the VIMOS-VLT Deep Survey (VVDS). We use mock catalogues extracted from the Millennium Simulation to study the potential systematics that might affect the overall distribution of the identified systems, and also to asses how well galaxy redshifts trace the line-of-sight velocity dispersion of the underlying mass overdensity. We train on these mock catalogues the adopted group-finding technique (the Voronoi-Delaunay Method, VDM), to recover in a robust and unbiased way the redshift and velocity dispersion distributions of groups and maximize the level of completeness (C) and purity (P) of the group catalogue. We identify 318(/144) VVDS groups with at least 2(/3) members within 0.2<=z<=1.0, globally with C=60% and P=50%. We use the group sample to study the redshift evolution of the fraction f_b_ of blue galaxies (U-B<=1) within 0.2<=z<=1 in both groups and in the whole ensemble of galaxies irrespectively of their environment.
- ID:
- ivo://CDS.VizieR/J/ApJ/539/577
- Title:
- Galaxy morphologies in Cl 1358+62
- Short Name:
- J/ApJ/539/577
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe the morphological composition of a sample of 518 galaxies in the field of Cl 1358+62 at z=0.33, drawn from a large Hubble Space Telescope mosaic covering 53 square arcminutes. The sample is complete to I=22, corresponding to M_V_=-18.5 in the rest frame. The galaxy morphologies have been independently classified by the authors of this paper and by Alan Dressler. Dressler's classifications place our work in context with the previous MORPHS study and allow us to estimate the scatter between different sets of visual classifications. We restrict most of our analysis to the brighter part of the sample, I<21 (M_V_<-19.5), where the scatter between the two sets of classifications is 1 in morphological type.
- ID:
- ivo://CDS.VizieR/J/AJ/122/621
- Title:
- Galaxy morphology in the CFRS
- Short Name:
- J/AJ/122/621
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The images of 229 galaxies in the Canada-France Redshift Survey have been classified on the DDO system. These observations were combined with previous classifications of galaxies with known redshifts in the Hubble Deep Field. The combined sample provides homogeneous morphological classifications for 425 galaxies of known redshift. The fraction of all galaxies that are of type E, S0, or E/S0 appears to remain approximately constant at ~17% over the redshift range 0.25<z<1.2. Over the same range, the fraction of irregular (Ir) galaxies increases from ~5% to ~12%. Part of this increase may be due to mild luminosity evolution of Ir galaxies. The frequency of mergers is found to rise by a factor of 2 or 3 over the redshift range covered by the present survey. These results are in qualitative agreement with those obtained previously by Brinchmann et al. (Cat. <J/ApJ/499/112>) using a coarser galaxy classification system.
