- ID:
- ivo://CDS.VizieR/VII/86A
- Title:
- Groups of Galaxies. I. Nearby Groups
- Short Name:
- VII/86A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog contains nearby groups of galaxies with outer number density enhancement greater than 20. The groups were searched using a whole sky catalog of 1312 galaxies brighter than mag 13.2 (B) with complete redshift information (Huchra et al. =1983ApJS...52...89H). Only groups containing more than two members are included. The catalogue includes equatorial coordinates, average radial velocities, and velocity dispersions for 92 nearby groups in the first file. A second file contains the results of a comparison between this catalog and de Vaucouleurs' (1975) catalog of nearby groups The Hubble constant was assumed 100km/s/Mpc.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/655/790
- Title:
- Groups of galaxies in 2MASS survey
- Short Name:
- J/ApJ/655/790
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of applying a percolation algorithm to the initial release of the Two Micron All Sky Survey Extended Source Catalog, using subsequently measured redshifts for almost all of the galaxies with K<11.25mag. This group catalog is based on the first near-IR all-sky flux-limited survey that is complete to |b|=5{deg}. We explore the dependence of the clustering on the length and velocity scales involved. The paper describes a group catalog, complete to a limiting redshift of 104km/s, created by maximizing the number of groups containing three or more members. A second catalog is also presented, created by requiring a minimum density contrast of {delta}{rho}/{rho}>=80 to identify groups. We identify known nearby clusters in the catalogs and contrast the groups identified in the two catalogs. We examine and compare the properties of the determined groups and verify that the results are consistent with the UZC-SSRS2 and northern CfA redshift survey group catalogs. The all-sky nature of the catalog will allow the development of a flow-field model based on the density field inferred from the estimated cluster masses.
- ID:
- ivo://CDS.VizieR/J/A+AS/119/391
- Title:
- Gunn photometry of seven clusters of galaxies
- Short Name:
- J/A+AS/119/391
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gunn g, r, i photometry for the 7 clusters MRC0254-274, Cl0317+15, MS0418.3-3 844, Cl1141-283, A1689, A3594, S0781B is presented. For each cluster we derived the spatial distribution properties obtaining the core radius and the concentration parameters. Color properties of the cluster galaxy population are also briefly discussed.
- ID:
- ivo://CDS.VizieR/J/A+A/569/A124
- Title:
- GUViCS. Ultraviolet Source Catalogs
- Short Name:
- J/A+A/569/A124
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we introduce the deepest and most extensive ultraviolet extragalactic source catalogs of the Virgo Cluster area to date. Archival and targeted GALEX imaging is compiled and combined to provide the deepest possible coverage over ~120deg^2^ in the NUV (lambda_eff_=2316{AA}) and ~40deg^2^ in the FUV (lambda_eff_=1539{AA}) between 180{deg}<=RA<=195{deg} and 0{deg}<=DE<=20{deg}. We measure the integrated photometry of 1770 extended UV sources of all galaxy types and use GALEX pipeline photometry for 1,230,855 point-like sources in the foreground, within, and behind the cluster. Extended source magnitudes are reliable to m_UV_~22, showing a ~0.01{sigma} difference from their asymptotic magnitudes. Point-like source magnitudes have a 1{sigma} standard deviation within ~0.2mag down to m_uv_~23. The point-like source catalog is cross-matched with large optical databases and surveys including the SDSS DR9 (>1 million Virgo Cluster sources), the Next Generation Virgo Cluster Survey (NGVS; >13 million Virgo Cluster sources), and the NED (~30,000 sources in the Virgo Cluster). We find that 69% of the entire UV point-like source catalog has a unique optical counterpart, 11% of which are stars and 0.01% (129) are Virgo cluster members that are neither in the VCC nor part of the bright CGCG galaxy catalog (i.e., m_pg_<14.5). These data are collected in three catalogs containing the UV extended sources, the UV point-like sources, and the most relevant optical parameters of UV-optically matched point-like sources for further studies from SDSS. The GUViCS catalogs provide a unique set of data for future work on UV and multiwavelength studies in the cluster and background environments.
- ID:
- ivo://CDS.VizieR/J/A+A/545/A16
- Title:
- Halpha3. Catalog and SFR in Virgo cluster
- Short Name:
- J/A+A/545/A16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present H{alpha}3 (acronym for H{alpha}-{alpha}{alpha}), an H{alpha} narrow-band imaging survey of ~400 galaxies selected from the HI Arecibo Legacy Fast ALFA Survey (ALFALFA) in the Local Supercluster, including the Virgo cluster. By using hydrogen recombination lines as a tracer of recent star formation, we aim to investigate the relationships between atomic neutral gas and newly formed stars in different environments (cluster and field), morphological types (spirals and dwarfs), and over a wide range of stellar masses (~10^7.5^-10^11.5^M_{sun}_). We image in H{alpha}+[NII] all the galaxies that contain more than 10^7^M_{sun}_ of neutral atomic hydrogen in the sky region 11h<R.A.<16h ; 4{deg}<Dec.<16{deg}; 350<cz<2000km/s using the San Pedro Martir 2m telescope. This survey provides a complete census of the star formation in HI rich galaxies of the local universe. We present the properties of the galaxy sample, together with H{alpha} fluxes and equivalent widths. We find an excellent agreement between the fluxes determined from our images in apertures of 3-arcsec diameter and the fluxes derived from the SDSS spectral database. From the H{alpha} fluxes corrected for galactic and internal extinction and for [NII] contamination we derive the global star formation rates (SFRs).
- ID:
- ivo://CDS.VizieR/J/ApJ/630/206
- Title:
- H{alpha} data for 3 EDisCS galaxy clusters
- Short Name:
- J/ApJ/630/206
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present H{alpha}-derived SFRs for three z~0.75 galaxy clusters. Our 1{sigma} flux limit corresponds to a star formation rate (SFR) of 0.10-0.24h^-2^_100_M_{Sun}/yr, and our minimum reliable H{alpha}+[NII] rest-frame equivalent width is 10{AA}. We show that H narrowband imaging is an efficient method for measuring star formation in distant clusters.
- ID:
- ivo://CDS.VizieR/J/ApJ/549/820
- Title:
- H{alpha} flux of ACCG 114 galaxies
- Short Name:
- J/ApJ/549/820
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a wide-field survey for H{alpha}-emitting galaxies in the cluster AC 114 at z=0.32. Spectra centered on H{alpha} at the cluster redshift have been obtained for 586 galaxies to I_tot_~22 out to a radius of ~h_50_^-1^Mpc. At most, only ~10% of these were found to be H{alpha}-emitting cluster members. These objects are predominantly blue and of late-type spiral morphology, consistent with them hosting star formation. However, ~65% of the cluster members classified morphologically as spirals (with HST) have no detectable H{alpha} emission; star formation and morphological evolution in cluster galaxies appear to be largely decoupled. Changes in the H{alpha} detection rate and the strength of H{alpha} emission with environment (as traced by local galaxy density) are found to be weak within the region studied. Star formation within the cluster members is also found to be strongly and uniformly suppressed with the rates inferred from the H{alpha} emission not exceeding 4M_{sun}_/yr, and AC 114's H{alpha} luminosity function being an order of magnitude below that observed for field galaxies at the same redshift. None of the galaxies detected have the high star formation rates associated with "starburst" galaxies; however, this may still be reconcilable with the known (8%+/-3%) fraction of "post-starburst" galaxies within AC 114, given the poorly determined but short lifetimes of starbursts and the possibility that much of the associated star formation is obscured by dust.
- ID:
- ivo://CDS.VizieR/J/A+A/384/383
- Title:
- H{alpha} galaxies in Abell 1367 and Coma
- Short Name:
- J/A+A/384/383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a deep wide field H{alpha} imaging survey of the central regions of the two nearby clusters of galaxies Coma and Abell 1367, taken with the WFC at the Prime Focus at the NT 2.5m telescope located at Observatorio de El Roque de los Muchachos (La Palma), on April 26th and 28th 2000. We determine for the first time the Schechter parameters of the H{alpha} luminosity function (LF) of cluster galaxies.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A46
- Title:
- Halpha images of 6 lenticular galaxies
- Short Name:
- J/A+A/659/A46
- Date:
- 04 Mar 2022 00:51:50
- Publisher:
- CDS
- Description:
- As part of the Virgo Cluster Survey Tracing Ionised Gas Emission, a blind narrow-band H{alpha}+[NII] imaging survey of the Virgo cluster carried out with MegaCam at the CFHT, we discovered eight massive (10^10^<~M_star_<~10^11^M_{sun}_) lenticular galaxies with prominent ionised gas emission features in their inner (a few kiloparsec) regions. These features are either ionised gas filaments similar to those observed in cooling flows (two galaxies), or they are thin discs with sizes 0.7<~R(H{alpha})<~2.0kpc (six galaxies), thus significantly smaller than those of the stellar disc (R(H{alpha})~=7-22%R_iso_(r)). The morphological properties of these discs are similar to those of the dust seen in absorption in high-resolution HST images. Using a unique set of multifrequency data, including new or archival ASTROSAT/UVIT, GALEX, HST, CFHT, Spitzer, and Herschel imaging data, combined with IFU (MUSE, ALMA) and long-slit (SOAR) spectroscopy, we show that while the gas that is located within these inner discs is photoionised by young stars, which signals ongoing star formation, the gas in the filamentary structures is shock ionised. The star formation surface brightness of these discs is similar to that observed in late-type galaxies. Because of their reduced size, however, these lenticular galaxies are located below the main sequence of unperturbed or cluster star-forming systems. By comparing the dust masses measured from absorption maps in optical images, from the Balmer decrement, or estimated by fitting the UV-to-far-IR spectral energy distribution of the target galaxies, we confirm that the dust masses derived from optical attenuation maps are heavily underestimated because of geometrical effects due to the relative distribution of the absorbing dust and the emitting stars. We also show that these galaxies have gas-to-dust ratios of G/D=~80_30_^320^, and that the star formation within these discs follows the Schmidt relation, but with an efficiency that is reduced by a factor of ~2.5. Using our unique set of multifrequency data, we discuss the possible origin of the ionised gas in these objects, which suggests multiple and complex formation scenarios for massive lenticular galaxies in clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/318/703
- Title:
- H-alpha in Abell 2390
- Short Name:
- J/MNRAS/318/703
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photometry is tabulated for 1189 galaxies in 19 OSIS-V (CFHT) images in the direction of the galaxy cluster Abell 2390. The images cover 270 sq. deg., and extend out to the virial radius of the cluster. Three narrow filters are used to determine the flux above the continuum between wavelengths 7897 and 8245 {AA}, corresponding to H-alpha at 0.2033<z<0.2563. The absolute flux values are uncertain by about 30% due to zero point uncertainty; we also tabulate the equivalent width which is independent of this zero point. Only strong emission line cluster members (equivalent width greater than about 50{AA}) are detectable, by design. Galaxies with spectra available from the CNOC survey (Abraham=1996ApJ...471..694A) are identified.
