- ID:
- ivo://CDS.VizieR/J/MNRAS/404/1490
- Title:
- Shapes of BCGs in nearby clusters shapes
- Short Name:
- J/MNRAS/404/1490
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We compare the apparent axial ratio distributions of the brightest cluster galaxies (BCGs) and normal ellipticals (Es) in our sample of 75 galaxy clusters from the WIde-field Nearby Galaxy-cluster Survey (WINGS). Most BCGs in our clusters (69 per cent) are classified as cD galaxies. The sample of cDs has been completed by 14 additional cDs (non-BCGs) we found in our clusters. We deproject the apparent axial ratio distributions of Es, BCGs and cDs using a bivariate version of the Lucy rectification algorithm, whose results are supported by an independent Monte Carlo technique. Finally, we compare the intrinsic shape distribution of BCGs to the corresponding shape distribution of the central part of cluster-sized dark matter haloes extracted from the GIF2 Lambda cold dark matter ({LAMBDA}CDM) N-body simulations (Gao et al., 2004MNRAS.355..819G).
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/344/602
- Title:
- Shape statistics of SDSS superclusters
- Short Name:
- J/MNRAS/344/602
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the supercluster shape properties of the recently compiled Sloan Digital Sky Survey (SDSS) cluster catalogue using an approach based on differential geometry. We detect superclusters by applying the percolation algorithm to observed cluster populations, extended out to z_max_<=0.23 in order to avoid selection biases. We utilize a set of shapefinders in order to study the morphological features of superclusters with >=8 cluster members and find that filamentary morphology is the dominant supercluster shape feature, in agreement with previous studies.
- ID:
- ivo://CDS.VizieR/J/A+AS/125/247
- Title:
- Shapley Concentration galaxies velocities
- Short Name:
- J/A+AS/125/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report velocity measurements of galaxies in this, the densest mass concentration within z=0.1, obtained with the multifiber spectrograph MEFOS at ESO, La Silla. We derive redshifts of a number of Abell clusters and draw implications for the supercluster structure. The clusters A3554, A3566, A3577 and AS718 are confirmed as members, while the clusters A3524, A3531, A3542, A3545 and A3549 are shown to be background systems and A3581 a foreground one
- ID:
- ivo://CDS.VizieR/J/A+A/622/A83
- Title:
- Sizes of infinity regions
- Short Name:
- J/A+A/622/A83
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Backreactions from large-scale inhomogeneities may provide an elegant explanation for the observed accelerated expansion of the universe without the need to introduce dark energy. We propose a cosmological test for a specific model of inhomogeneous cosmology, called timescape cosmology. Using large-scale galaxy surveys such as SDSS and 2MRS, we test the variation of expansion expected in the {Lambda}-CDM model versus a more generic differential expansion using our own calibrations of bounds suggested by timescape cosmology. Our test measures the systematic variations of the Hubble flow towards distant galaxies groups as a function of the matter distribution in the lines of sight to those galaxy groups. We compare the observed systematic variation of the Hubble flow to mock catalogues from the Millennium Simulation in the case of the {Lambda}-CDM model, and a deformed version of the same simulation that exhibits more pronounced differential expansion. We perform a series of statistical tests, ranging from linear regressions to Kolmogorov-Smirnov tests, on the obtained data. They consistently yield results preferring {Lambda}-CDM cosmology over our approximated model of timescape cosmology. Our analysis of observational data shows no evidence that the variation of expansion differs from that of the standard {Lambda}-CDM model.
- ID:
- ivo://CDS.VizieR/J/MNRAS/327/249
- Title:
- SMAC. II. Fundamental Plane photometric data
- Short Name:
- J/MNRAS/327/249
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new R-band photometric data for 447 galaxies, gathered for the Streaming Motions of Abell Clusters (SMAC) project. The data comprise 629 individual measurements of the Fundamental Plane (FP) parameters effective radius (Re) and surface brightness (<{mu}>_e_), derived from R^1/4^-law profile fitting. More than a third of the galaxies were observed more than once.
- ID:
- ivo://CDS.VizieR/J/MNRAS/327/265
- Title:
- SMAC. III. Fundamental Plane catalog
- Short Name:
- J/MNRAS/327/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the construction of a new, standardized all-sky catalogue of Fundamental Plane (FP) data from early-type galaxies in clusters, for peculiar velocity applications. This catalogue is based on a compilation of spectroscopic and photometric data consisting of data reported in previous papers of this series, plus data from published sources.
- ID:
- ivo://CDS.VizieR/J/A+A/281/375
- Title:
- Small-size radio galaxies in clusters
- Short Name:
- J/A+A/281/375
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/ApJS/240/1
- Title:
- SMUDGes. I. First results in the Coma Cluster
- Short Name:
- J/ApJS/240/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a homogeneous catalog of 275 large (effective radius >~5.3") ultra-diffuse galaxy (UDG) candidates lying within an ~290deg^2^ region surrounding the Coma Cluster. The catalog results from our automated postprocessing of data from the Legacy Surveys, a three-band imaging survey covering 14000deg^2^ of the extragalactic sky. We describe a pipeline that identifies UDGs and provides their basic parameters. The survey is as complete in these large UDGs as previously published UDG surveys of the central region of the Coma Cluster. We conclude that the majority of our detections are at roughly the distance of the Coma Cluster, implying effective radii >=2.5kpc, and that our sample contains a significant number of analogs of DF44 (SMDG1300580+265835), where the effective radius exceeds 4kpc, both within the cluster and in the surrounding field. The g-z color of our UDGs spans a large range, suggesting that even large UDGs may reflect a range of formation histories. A majority of the UDGs are consistent with being lower stellar mass analogs of red sequence galaxies, but we find both red and blue UDG candidates in the vicinity of the Coma Cluster and a relative overabundance of blue UDG candidates in the lower-density environments and the field. Our eventual processing of the full Legacy Surveys data will produce the largest, most homogeneous sample of large UDGs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/434/1443
- Title:
- SN Ia inside rich galaxy clusters
- Short Name:
- J/MNRAS/434/1443
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used the Gaussian Mixture Brightest Cluster Galaxy catalogue and Sloan Digital Sky Survey-II supernovae data with redshifts measured by the Baryon Oscillation Spectroscopic Survey to identify 48 Type Ia supernovae (SNe Ia) residing in rich galaxy clusters and compare their properties with 1015 SNe Ia in the field. Their light curves were parametrized by the SALT2 model and the significance of the observed differences was assessed by a resampling technique. To test our samples and methods, we first looked for known differences between SNe Ia residing in active and passive galaxies. We confirm that passive galaxies host SNe Ia with smaller stretch, weaker colour-luminosity relation [{beta} of 2.54(22) against 3.35(14)], and that are ~ 0.1mag more luminous after stretch and colour corrections. We show that only 0.02 percent of random samples drawn from our set of SNe Ia in active galaxies can reach these values. Reported differences in the Hubble residuals scatter could not be detected, possibly due to the exclusion of outliers. We then show that, while most field and cluster SNe Ia properties are compatible at the current level, their stretch distributions are different (~3{sigma}): besides having a higher concentration of passive galaxies than the field, the cluster's passive galaxies host SNe Ia with an average stretch even smaller than those in field passive galaxies (at 95 percent confidence). We argue that the older age of passive galaxies in clusters is responsible for this effect since, as we show, old passive galaxies host SNe Ia with smaller stretch than young passive galaxies (~4{sigma}).
- ID:
- ivo://CDS.VizieR/J/ApJS/191/340
- Title:
- Southern Cosmology Survey. II.
- Short Name:
- J/ApJS/191/340
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of 105 rich and massive (M>3x10^14^M_{sun}_) optically selected clusters of galaxies extracted from 70deg^2^ of public archival griz imaging from the Blanco 4m telescope acquired over 45 nights between 2005 and 2007. We use the clusters' optically derived properties to estimate photometric redshifts, optical luminosities, richness, and masses. We complement the optical measurements with archival XMM-Newton and ROSAT X-ray data which provide additional luminosity and mass constraints on a modest fraction of the cluster sample. Two of our clusters show clear evidence for central lensing arcs; one of these has a spectacular large diameter, nearly complete Einstein Ring surrounding the brightest cluster galaxy.
