J/AJ/115/6 J/AJ/115/6 Hercules supercluster kinematics P Barmby J P Huchra Astron. J. 115 6 1998 1998AJ....115....6B VII/99 : Radial Velocities of Galaxies (Palumbo+ 1986) VII/112 : RC2 Catalogue (de Vaucouleurs+ 1976) VII/155 : RC3 Catalogue (de Vaucouleurs+ 1991) VII/172 : First Byurakan Survey (FBS) (Markarian+, 1989) J/A+AS/109/537 : Redshift survey of faint galaxies (Hopp+, 1995) Clusters, galaxy Photometry, CCD Radial velocities cosmology: observations dark matter galaxies: clusters: individual (Hercules) The Hercules supercluster consists of the Abell clusters A2147, A2151, and A2152. Previous studies of the kinematics have been confounded by the difficulty of correctly assigning galaxies to the individual clusters, which are not well separated. Our study has a total of 468 available velocities for galaxies in the region, 175 of them new. There are 414 galaxies in the supercluster, about 3 times the number used in the previous supercluster study. We verify the existence of the three individual clusters and compute their individual dynamical parameters. We investigate several techniques for assigning galaxy membership to clusters in this crowded field. We use the KMM mixture-modeling algorithm to separate the galaxies into clusters; we find that A2152 has a higher mean velocity than previous studies have reported. A2147 and A2152 also have lower velocity dispersions: 821^+68^_-55_ and 715^+81^_-61_km/s, respectively. The assignment of galaxies to either A2152 or A2147 requires velocity and position information. We study the kinematics of the supercluster using the two-body formalism of Beers, Geller, & Huchra (1982ApJ...257..323B) and conclude that A2147 and A2151 are probably bound to each other and that the supercluster as a whole may also be bound. The mass of the supercluster, if bound, is (7.6+/-2.0)x10^15^h^-1^M_{sun}_; with the supercluster luminosity, (1.4+/-0.2)x10^13^h^-2^L_{sun}_, this yields {OMEGA}=0.34+/-0.1.

Name Galaxy name --- RAh Right ascension (J2000.0) h RAm Right ascension (J2000.0) min RAs Right ascension (J2000.0) s DE- Declination sign --- DEd Declination (J2000.0) deg DEm Declination (J2000.0) arcmin DEs Declination (J2000.0) arcsec Rmag R magnitude mag HV Heliocentric velocity km/s e_HV rms uncertainty on HV km/s MType Morphological type --- r_HV Velocity source, see refs.dat --- Name Galaxy name --- RAh Right ascension (J2000.0) h RAm Right ascension (J2000.0) min RAs Right ascension (J2000.0) s DE- Declination sign --- DEd Declination (J2000.0) deg DEm Declination (J2000.0) arcmin DEs Declination (J2000.0) arcsec Bmag B magnitude mag B-R B-R colour index mag RefCode Reference code --- Text Text of reference (including the 19-digit bibcode) --- table1.texLaTeX Version of Table 1 table1.psPostscript version of Table 1 Patricia Bauer CDS 1998Mar05 UNKNOWN UNKNOWN * 05-Mar-1998: Copied from the electronic version of AJ http://cdsaas.u-strasbg.fr:2001/AJ/journal/contents/v115n1.html * 02-Jun-1998 (from Pauline Barmby, <pbarmby@cfa.harvard.edu>) Table 1, Galaxies in the Hercules Supercluster, had several errors, including typographical errors in coordinates, object misidentifications, and duplicate entries. We have corrected these errors and determined that they not do not affect the conclusions of the paper. A corrected version of the table, containing 458 galaxies with velocities (171 new velocities) is available in the electronic version of the paper. We thank M. Schmitz for bringing some of the errors to our attention. J_AJ_115_6.xml