- ID:
- ivo://CDS.VizieR/J/A+A/637/A31
- Title:
- Cluster in superclusters of galaxies
- Short Name:
- J/A+A/637/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characterization of the internal structure of the superclusters of galaxies (walls, filaments and knots where the clusters are located) is paramount for understanding the formation of the Large Scale Structure and for outlining the environment where galaxies evolved in the last Gyr. (i) To detect the compact regions of high relative density (clusters and rich groups of galaxies); (ii) to map the elongated structures of low relative density (filaments, bridges and tendrils of galaxies); (iii) to characterize the galaxy populations on filaments and study the environmental effects they are subject to. We employed optical galaxies with spectroscopic redshifts from the SDSS-DR13 inside rectangular boxes encompassing the volumes of a sample of 46 superclusters of galaxies, up to z=0.15. A virial approximation was applied to correct the positions of the galaxies in the redshift space for the "finger of God" projection effect. Our methodology implements different classical pattern recognition and machine learning techniques (Voronoi tessellation, hierarchical clustering, graph-network theory, minimum spanning trees, among others), pipelined in the Galaxy Systems-Finding algorithm and the Galaxy Filaments-Finding algorithm. We detected in total 2705 galaxy systems (clusters and groups, of which 159 are new) and 144 galaxy filaments in the 46 superclusters of galaxies. The filaments we detected have a density contrast above 3, with a mean value around 10, a radius of about 2.5h_70_^-1^Mpc and lengths between 9 and 130h_70_^-1^Mpc. Correlations between the galaxy properties (mass, morphology and activity) and the environment in which they reside (systems, filaments and the dispersed component) suggest that galaxies closer to the skeleton of the filaments are more massive by up to 25% compared to those in the dispersed component; 70% of the galaxies in the filament region present early type morphologies and the fractions of active galaxies (both AGN and SF) seem to decrease as galaxies approach the filament. Our results support thee idea that galaxies in filaments are subject to environmental effects leading them to be more massive (probably due to larger rates of both merging and gas accretion), less active both in star formation and nuclear activity, and prone to the density-morphology relation. These results suggest that preprocessing in large scale filaments could have significant effects on galaxy evolution.
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Search Results
- ID:
- ivo://irsa.ipac/Spitzer/Images/CLASH
- Title:
- Cluster Lensing And Supernova survey with Hubble
- Short Name:
- CLASH
- Date:
- 27 Oct 2022 19:00:00
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Cluster Lensing And Supernova survey with Hubble (CLASH) is an HST Multi-Cycle Treasury program (PI: Marc Postman) to survey 25 massive galaxy clusters at 16 wavelengths spanning from the near-UV to the near-IR (Postman et al. (2012)). The full HST dataset and associated catalogs and gravitational lens models are available at MAST. A series of programs with Spitzer have covered all CLASH galaxy clusters with IRAC Channels 1 and 2 (3.6 and 4.5 micron). Several of the targets include Channels 3 and 4 (5.8 and 8 micron) data. Spitzer mosaics, catalogs, and PSF images are available at IRSA.
- ID:
- ivo://CDS.VizieR/J/AN/327/365
- Title:
- Clusters and groups of galaxies in 2dF
- Short Name:
- J/AN/327/365
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We create a new catalogue of groups and clusters, applying the friends-to-friends method to the 2dF GRS final release. We investigate various selection effects due to the use of a magnitude limited sample. For this purpose we follow the changes in group sizes and mean galaxy number densities within the groups when shifting nearby observed groups to larger distances. We study the distribution of sizes of dark matter haloes in N-body simulations and compare properties of these haloes and the 2dF groups.
- ID:
- ivo://CDS.VizieR/J/MNRAS/259/233
- Title:
- Cluster SC2008-57(A3667)
- Short Name:
- J/MNRAS/259/233
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (Abstract of the paper) We present the results of photometric and spectroscopic observations of the cluster of galaxies SC2008-57 (A3667). The observations have resulted in a catalogue with positions and magnitudes for 203 galaxies, complete at b_25 = 18.0, and radial velocities for 128 galaxies, 91 per cent complete at b_25 = 17.5. The cluster can be classified as type L because its galaxy distribution is highly flattened. It shows two strong concentrations: a main concentration, centred on the cluster brightest galaxy (a D galaxy) and coincident with the peak of X-ray emission, and a substructure around the second brightest galaxy (also a D galaxy). Most of the galaxies in this substructure seem to be bound to the second-brightest galaxy, forming a dynamical subunit inside the cluster. The extreme flattening of the cluster may at least partially be due to the presence of the substructure. The cluster also shows evidence for luminosity segregation, with the brightest galaxies being preferentially found in high galaxy density regions. Most of the luminosity segregation, however, is produced by galaxies associated with the two clumps around the D galaxies, suggesting that dynamical friction is effective in subclusters with low velocity dispersions and may be associated with the formation of D galaxies. The velocity dispersion of SC2008-57 is high, about 1200 km/s, but consistent with the observed X-ray luminosity. The cluster mass, derived using several estimators, is about 2.6 x 10^15 M_solar. Both the cluster mass and velocity dispersion may be overestimates due to the presence of the substructure.
- ID:
- ivo://CDS.VizieR/J/A+A/616/A42
- Title:
- Clusters candidates from PSZ1 catalogue
- Short Name:
- J/A+A/616/A42
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have identified new clusters and characterized previously unknown Planck Sunyaev-Zeldovich (SZ) sources from the first Planck catalogue of SZ sources (PSZ1). The results presented here correspond to an optical follow-up observational programme developed during approximately one year (2014) at Roque de los Muchachos Observatory, using the 2.5m Isaac Newton telescope, the 3.5m Telescopio Nazionale Galileo, the 4.2m William Herschel telescope and the 10.4m Gran Telescopio Canarias. We have characterized 115 new PSZ1 sources using deep optical imaging and spectroscopy. We adopted robust criteria in order to consolidate the SZ counterparts by analysing the optical richness, the 2D galaxy distribution, and velocity dispersions of clusters. Confirmed counterparts are considered to be validated if they are rich structures, well aligned with the Planck PSZ1 coordinate and show relatively high velocity dispersion. Following this classification, we confirm 53 clusters, which means that 46% of this PSZ1 subsample has been validated and characterized with this technique. Sixty-two SZ sources (54% of this PSZ1 subset) remain unconfirmed. In addition, we find that the fraction of unconfirmed clusters close to the galactic plane (at |b|<25{deg}) is greater than that at higher galactic latitudes (|b|>25{deg}), which indicates contamination produced by radio emission of galactic dust and gas clouds on these SZ detections. In fact, in the majority of the cases, we detect important galactic cirrus in the optical images, mainly in the SZ target located at low galactic latitudes, which supports this hypothesis.
- ID:
- ivo://CDS.VizieR/J/ApJS/199/34
- Title:
- Clusters of galaxies in SDSS-III
- Short Name:
- J/ApJS/199/34
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the photometric redshifts of galaxies from the Sloan Digital Sky Survey III (SDSS-III), we identify 132684 clusters in the redshift range of 0.05<=z<0.8. Monte Carlo simulations show that the false detection rate is less than 6% for the whole sample. The completeness is more than 95% for clusters with a mass of M_200_>1.0x10^14^M_{sun}_ in the redshift range of 0.05<=z<0.42, while clusters of z>0.42 are less complete and have a biased smaller richness than the real one due to incompleteness of member galaxies. We compare our sample with other cluster samples, and find that more than 90% of previously known rich clusters of 0.05<=z<0.42 are matched with clusters in our sample. Richer clusters tend to have more luminous brightest cluster galaxies (BCGs). Correlating with X-ray and the Planck data, we show that the cluster richness is closely related to the X-ray luminosity, temperature, and Sunyaev-Zel'dovich measurements. Comparison of the BCGs with the SDSS luminous red galaxy (LRG) sample shows that 25% of LRGs are BCGs of our clusters and 36% of LRGs are cluster member galaxies. In our cluster sample, 63% of BCGs of r_petro_<19.5 satisfy the SDSS LRG selection criteria.
- ID:
- ivo://CDS.VizieR/J/ApJS/95/401
- Title:
- Clusters of galaxies position angles
- Short Name:
- J/ApJS/95/401
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The position angles of a large number of Abell and Shectman clusters, identified in the Lick map as surface galaxy-density enhancements, are estimated. I determine the major axis orientation of a total of 637 clusters, of which 448 are Shectman clusters (202 of which are also Abell clusters) and 189 are Abell clusters not originally detected by Shectman due to his adopted density threshold. Using published redshifts for 277 of these clusters I have detected strong nearest neighbor alignments over scales up to ~15h^-1^Mpc at a>~2.5-3{sigma} significance level, while quite weak alignments are detected even up to ~60h^-1^Mpc. A more significant alignment signal (~4{sigma}) is detected among all neighbors residing in superclusters and having separations <~ 10h^-1^Mpc. Again, weaker but significant alignments are found when larger separations are considered. Since my cluster sample is neither volume limited nor redshift complete (which would have tended to wash out any real alignment signal), the alignments detected should reflect a real and possibly a stronger underline effect.
- ID:
- ivo://CDS.VizieR/J/A+AS/110/313
- Title:
- Clusters of galaxies properties. II.
- Short Name:
- J/A+AS/110/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present F band photometry, from digitized 48-inch Palomar plates, of 1167 galaxies brighter than m_3_ +3 in 10 Abell clusters. For each galaxy, absolute coordinates, magnitude, size, ellipticity and orientation are given. For each cluster we provide finding charts and contour maps of the galaxy surface density.
- ID:
- ivo://CDS.VizieR/J/A+A/286/17
- Title:
- 21cm obs. of galaxies in Psc-Per Supercl.
- Short Name:
- J/A+A/286/17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper presents the first results of a 21cm survey of newly discovered optically selected galaxies behind the Milky Way. We present 40 radial velocities of the new galaxies and 15 velocities of UGC and MCG galaxies in a region where the well known Pisces-Perseus-Supercluster (PPScl) is supposed to be veiled by galactic extinction (80deg<~l<~110deg). Twenty-four galaxies have radial velocities between 4000 and 6000 km/s that fit to the values usually accepted for the PPScl. We could pursue this supercluster at least to b=-5 deg around l=90 deg.
- ID:
- ivo://CDS.VizieR/J/MNRAS/324/1131
- Title:
- 22-cm radio survey of A3528
- Short Name:
- J/MNRAS/324/1131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report and discuss the results of a 22-cm radio survey carried out with the Australia Telescope Compact Array (ATCA) covering the A3528 complex, a chain formed by the merging ACO clusters A3528-A3530-A3532, located in the central region of the Shapley Concentration. Simultaneous 13-cm observations are also presented. Our final catalogue includes a total of 106 radio sources above the flux density limit of 0.8mJy. By cross-correlation with optical and spectroscopic catalogues we found 32 optical counterparts, nine of them belonging to the A3528 complex.
