- ID:
- ivo://CDS.VizieR/J/A+AS/94/327
- Title:
- Nearby clusters of galaxies. I.
- Short Name:
- J/A+AS/94/327
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A study of the properties of nearby clusters of galaxies has been undertaken. This paper describes the data, derived from automated scans of photographic plates. Different methods for the evaluation of cluster center, ellipticity and orientation are compared and errors are estimated by Monte Carlo simulations. We present the results of the analysis of 1256 galaxies brighter than m_3_+3 in eight Abell clusters. We find that different methods give consistent estimates of ellipticity and orientation, provided the radial dependence of these quantities is taken into account. We also find that central densities are consistent with isothermal fits if the center is selected as the baricenter of the cluster. For each galaxy, rectangular coordinates, magnitude, size, ellipticity and orientation are given. For each cluster we provide identification maps and contour maps of galaxy surface density.
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- ID:
- ivo://CDS.VizieR/J/A+AS/125/459
- Title:
- Nearby clusters of galaxies properties. III.
- Short Name:
- J/A+AS/125/459
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper is the third of a series (Trevese et al. 1992, Paper I, Cat. <J/A+AS/94/327>, Flin et al. 1995, Cat. <J/A+AS/110/313>, Paper II, presenting F band photometry, from digitized 48-inch Palomar plates, of the galaxies brighter than m_3_+3 in a 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. In the present paper we analyze 15 new clusters and provide the absolute alpha and delta coordinates of the galaxies of 8 Abell clusters, studied in pap. I, which were published with relative coordinates only. In the electronic version, the tables of the 8 clusters of pap. I are written in the same format of papers II and III.
- ID:
- ivo://CDS.VizieR/J/MNRAS/471/4990
- Title:
- Nearby galaxy clusters X-ray point sources
- Short Name:
- J/MNRAS/471/4990
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work, we studied 10 nearby (z<=0.038) galaxy clusters to understand possible interactions between hot plasma and member galaxies. A multi-band source detection was applied to detect point-like structures within the intra-cluster medium. We examined the spectral properties of a total of 391 X-ray point sources within each cluster's potential well. log N versus log S was studied in the energy range 2-10 keV to measure X-ray overdensities. Optical overdensities were also calculated to solve suppression/triggering phenomena for nearby galaxy clusters. X-ray and optical flux/luminosity properties (X/O, L_X_/L_B_ and L_X_/L_K_) were investigated for optically identified member galaxies. The X-ray luminosities of our point sources were found to be faint [40.08<=log(L_X_)<=42.39erg/s]. The luminosity range of point sources reveals possible contributions to X-ray emission from low-luminosity active galactic nuclei, X-ray binaries and star formation. We estimated ~2 times higher X-ray overdensities from galaxies within galaxy clusters compared to fields. Our results demonstrate that optical overdensities are much higher than X-ray overdensities at a cluster's centre, whereas X-ray overdensities increase through the outskirts of clusters. We conclude that high pressure from a cluster's centre affects the balance of galaxies and they lose a significant amount of their fuel. As a result, the clustering process quenches the X-ray emission of the member galaxies. We also find evidence that the existence of X-ray bright sources within a cluster environment can be explained by two main phenomena: contributions from off-nuclear sources and/or active galactic nucleus (AGN) triggering caused by galaxy interactions rather than AGN fuelling.
684. Nearby galaxy flows
- ID:
- ivo://CDS.VizieR/J/ApJS/80/479
- Title:
- Nearby galaxy flows
- Short Name:
- J/ApJS/80/479
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Supporting material for an article in the main journal is presented. One table gives measured galaxy distances used to construct a map of observed peculiar velocities, and another table gives a grid of the distribution of light used to construct a map of expected peculiar velocities. A preferred model was developed which gave a best fit between these maps, and this model has been used to generate output kinematic distances which are recorded here for groups and individual galaxies with V_0_<3000km/s.
- ID:
- ivo://CDS.VizieR/J/ApJ/543/178
- Title:
- Nearby Optical Galaxy (NOG) sample
- Short Name:
- J/ApJ/543/178
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we describe the Nearby Optical Galaxy (NOG) sample, which is a complete, distance-limited (cz<=6000km/s) and magnitude-limited (B<=14) sample of ~7000 optical galaxies. The sample covers 2/3 (8.27sr) of the sky (|b|>20{deg}) and appears to have a good completeness in redshift (97%). We select the sample on the basis of homogenized corrected total blue magnitudes in order to minimize systematic effects in galaxy sampling. We identify the groups in this sample by means of both the hierarchical and the percolation "friends-of-friends" methods. The resulting catalogs of loose groups appear to be similar and are among the largest catalogs of groups currently available. Most of the NOG galaxies (~60%) are found to be members of galaxy pairs (~580 pairs for a total of ~15% of objects) or groups with at least three members (~500 groups for a total of ~45% of objects). About 40% of galaxies are left ungrouped (field galaxies). We illustrate the main features of the NOG galaxy distribution. Compared to previous optical and IRAS galaxy samples, the NOG provides a denser sampling of the galaxy distribution in the nearby universe. Given its large sky coverage, the identification of groups, and its high-density sampling, the NOG is suited to the analysis of the galaxy density field of the nearby universe, especially on small scales.
- ID:
- ivo://CDS.VizieR/J/AJ/118/2014
- Title:
- Nearby poor clusters of galaxies catalog
- Short Name:
- J/AJ/118/2014
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A catalog of 732 optically selected, nearby poor clusters of galaxies covering the entire sky north of -3{deg} declination is presented. The poor clusters, called WBL clusters, were identified as concentrations of three or more galaxies with photographic magnitudes brighter than 15.7, possessing a galaxy surface overdensity of 10^4/3^. These criteria are consistent with those used in the identification of the original Yerkes poor clusters, and this new catalog substantially increases the sample size of such objects. These poor clusters cover the entire range of galaxy associations up to and including Abell clusters, systematically including poor and rich galaxy systems spanning over 3 orders of magnitude in the cluster mass function. As a result, this new catalog contains a greater diversity of richness and structures than other group catalogs, such as the Hickson and Yerkes catalogs. The information on individual galaxies includes redshifts and cross-references to other galaxy catalogs. The entries for the clusters include redshift (where available) and cross-references to other group and cluster catalogs.
- ID:
- ivo://CDS.VizieR/J/MNRAS/368/534
- Title:
- Near-infrared study of CIZA J1324.7-5736
- Short Name:
- J/MNRAS/368/534
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the result of a deep near-infrared survey of the newly identified X-ray luminous cluster of galaxies CIZA J1324.7-5736 in the Great Attractor (GA) region. In a 35x35arcmin^2^ region, 111 galaxy candidates with r(Ks20)>3arcsec are identified.
- ID:
- ivo://CDS.VizieR/J/ApJ/750/93
- Title:
- Near-IR observations of XMM-LSS J02182-05102
- Short Name:
- J/ApJ/750/93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss the structural and morphological properties of galaxies in a z=1.62 proto-cluster using near-IR imaging data from Hubble Space Telescope Wide Field Camera 3 data of the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). The cluster galaxies exhibit a clear color-morphology relation: galaxies with colors of quiescent stellar populations generally have morphologies consistent with spheroids, and galaxies with colors consistent with ongoing star formation have disk-like and irregular morphologies. The size distribution of the quiescent cluster galaxies shows a deficit of compact (<~1kpc), massive galaxies compared to CANDELS field galaxies at z=1.6. As a result, the cluster quiescent galaxies have larger average effective sizes compared to field galaxies at fixed mass at greater than 90% significance. Combined with data from the literature, the size evolution of quiescent cluster galaxies is relatively slow from z=~1.6 to the present, growing as (1+z)^-0.6+/-0.1^. If this result is generalizable, then it implies that physical processes associated with the denser cluster region seem to have caused accelerated size growth in quiescent galaxies prior to z=1.6 and slower subsequent growth at z<1.6 compared to galaxies in the lower density field. The quiescent cluster galaxies at z=1.6 have higher ellipticities compared to lower redshift samples at fixed mass, and their surface-brightness profiles suggest that they contain extended stellar disks. We argue that the cluster galaxies require dissipationless (i.e., gas-poor or "dry") mergers to reorganize the disk material and to match the relations for ellipticity, stellar mass, size, and color of early-type galaxies in z<1 clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/446/97
- Title:
- NEP Distant Cluster Radio Galaxies
- Short Name:
- J/A+A/446/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A complete sample of 18 X-ray selected clusters of galaxies belonging to the ROSAT North Ecliptic Pole (NEP) survey has been observed with the Very Large Array at 1.4GHz in B configuration. These are the most distant clusters in the X-ray survey with redshift in the range 0.3<z<0.8. Seventy-nine radio sources are detected within half an Abell radius with an observed peak brightness >=0.17mJy/beam, except for three sources, belonging to the same cluster, which have a higher peak brightness limit of 0.26mJy/beam. The NEP field source counts are in good agreement with the source counts of a comparison survey, the VLA-VIRMOS deep field survey, indicating that the NEP sample is statistically complete. Thirty-two out of the 79 sources are within 0.2 Abell radii, twenty-two of them are considered cluster members based on spectroscopic redshifts or their optical magnitude and morphological classification. The cluster radio galaxies are used to construct the Radio Luminosity Function (RLF) of distant X-ray selected clusters. A comparison with two nearby cluster RLFs shows that the NEP RLF lies above the local ones, has a steeper slope at low radio powers (<=10^24^W/Hz) and shows no evidence for a break at about 6x10^24^W/Hz which is observed in the nearby cluster RLFs. We discuss briefly the origin and possible explanations of the differences observed in the radio properties of nearby and distant clusters of galaxies. The main result of this study is that the RLF of the distant X-ray clusters is very different from that of the local rich Abell clusters.
- ID:
- ivo://CDS.VizieR/J/A+A/645/A95
- Title:
- NEP raster ROSAT X-ray/Optical catalog
- Short Name:
- J/A+A/645/A95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The North-Ecliptic Pole is an important region for extragalactic surveys. Deep/wide contiguous surveys are being performed by several space observatories. We analyse all ROSAT pointed and survey observations within 40deg^2^ around the NEP, restricting the field-of-view to the inner 30' radius. We obtain an X-ray catalogue of 805 sources with 0.5-2keV fluxes >2.9*10^-15^erg/cm^2^/s, a factor of three deeper than the ROSAT All-Sky Survey in this field. The sensitivity and angular resolution of our data are comparable to the eROSITA All-Sky Survey expectations. The 50% position error radius of the sample of X-ray sources is ~10". We use HEROES optical and near-infrared imaging photometry from Subaru and CFHT telescopes together with literature catalogues and a new deep and wide Spitzer survey in the field to identify X-ray sources and calculate photometric redshifts for the candidate counterparts. In particular we utilize mid-IR colours to identify AGN X-ray counterparts. Despite relatively large error circles and faint counterparts, confusion and systematic errors, we obtain a rather reliable catalogue of 766 optical counterparts, redshifts and optical classifications. We find a new population of luminous absorbed X-ray AGN at large redshifts, not recognized in previous X-ray surveys, but identified in our work due to the unique combination of survey solid angle, X-ray sensitivity and multiwavelength photometry. We also use the WISE and Spitzer photometry to identify a sample of 185 AGN selected purely through mid-IR colours, most of which are not detected by ROSAT. Their redshifts and upper limits to X-ray luminosity and X-ray-to-optical flux ratios are even higher than for the new class of X-ray selected luminous type 2 AGN (AGN2); they are probably a natural extension of this sample. This unique dataset is important as a reference sample for future deep surveys in the NEP region, in particular for eROSITA and also for Euclid and SPHEREX. We predict that most of the absorbed distant AGN should be readily picked up by eROSITA, but they require sensitive mid-IR imaging to be recognized as optical counterparts.
