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The galaxy cluster Abell 426 (Perseus). A catalogue of 660 galaxy positions, isophotal magnitudes and morphological types
We present a homogeneous catalogue of galaxies in the field of thenearby galaxy cluster A 426 (Perseus) based on a survey of digitisedSchmidt plates taken with the Tautenburg 2 m telescope in the B band.Accurate positions, morphological types, B25 isophotalmagnitudes, angular radii and position angles are given for 660 galaxieswithin a field of about 10 square-degrees, centred on alpha = 3() h 21()min, delta = 41degr 33' (J2000). When available, the radial velocity andthe most common name taken from NED or PGC are included. The cataloguecomprises galaxies brighter than B25~19.5. The estimatedlimit of completeness is B25~18. Two thirds of the galaxiesare published for the first time. The galaxy positions are measured witha mean accuracy of 0farcs5 , the photometric accuracy is of the order of0.1 to 0.2 mag depending on image crowding and galaxy shape.Morphological properties were evaluated from the visual inspections ofboth deep images obtained from the digital co-addition of a large numberof plates and higher-resolution images from single plates taken undergood seeing conditions. The superimposed images unveil faint structuresdown to mu_B ~ 27 mag arcsec(-2) . The catalogue is applied to a studyof statistical properties of the galaxies in A 426: projecteddistribution of morphological types, segregation of morphological types,position of the cluster centre, distribution of galaxy position angles,type-dependent luminosity functions, and total B-luminosity of the thecluster. In agreement with previous studies, we find a relativespiral-deficiency in the central region (r <~ 30'). The percentage ofidentified S+Irr increases, however, increases from 30% in the centre tomore than 50% in the outer parts. The projected distributions of early-and late-type galaxies are not co-centred. The total luminosity of allsupposed member galaxies in the surveyed area is estimated to(6.5+/-0.9)\ 10(12) x h50(-2) blue solar luminosities. We donot analyse in detail possible substructures in the projecteddistribution of galaxies. However, we found a pronounced clump ofgalaxies at alpha (J2000.0) = 3() h20fm4 , delta (J2000.0) = 43degr4 ',which is shown to be a background cluster at z~ 0.050. The catalogue isonly available in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html } \fnmsep \thanks{ Based onobservations made with the 2\,m telescope of the ThüringerLandessternwarte Tautenburg, Germany, and with the 2.2\,m telescope ofthe German-Spanish Astronomical Centre, Calar Alto, Spain.
| An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
| General study of group membership. II - Determination of nearby groups
We present a whole sky catalog of nearby groups of galaxies taken fromthe Lyon-Meudon Extragalactic Database. From the 78,000 objects in thedatabase, we extracted a sample of 6392 galaxies, complete up to thelimiting apparent magnitude B0 = 14.0. Moreover, in order to considersolely the galaxies of the local universe, all the selected galaxieshave a known recession velocity smaller than 5500 km/s. Two methods wereused in group construction: a Huchra-Geller (1982) derived percolationmethod and a Tully (1980) derived hierarchical method. Each method gaveus one catalog. These were then compared and synthesized to obtain asingle catalog containing the most reliable groups. There are 485 groupsof a least three members in the final catalog.
| Isophotal shapes of early-type galaxies. II - The Perseus Cluster
We present the results of an isophotal shape analysis of a sample of 91early-type galaxies belonging to the Perseus Cluster, using CCD R and Vimages obtained in very good seeing conditions. This survey uncoversfine details in the structure of a large percentage of these objects,including disks, bars and even spiral arms, so that a large variety ofmorphological types is proposed. A very conservative upper limit for thepercentage of galaxies of the whole sample showing no deviations fromellipticity is given to be 20 percent. A lower limit for the detectionof bars among galaxies newly classified as S0's or spirals is about 30percent.
| The pattern of gas deficiency in cluster spirals - The correlation of H I and X-ray properties
The neutral hydrogen content of spiral galaxies is investigated as afunction of their location with six nearby rich clusters. Previousfindings that H I deficiency varies with projected radius from thecluster center are confirmed, but no correlation between H I depletionand velocity relative to the cluster is seen. The dependence of H Ideficiency on radius is monotonic; the most H I-poor objects are locatedclose to the cluster center. The current data, however, cannot be usedto distinguish between inbred and evolutionary gas deficiency mechanismsor among different environmental processes. Indications are found thatenvironmental effects on spirals, if present at all, only modify theimprint left at the time of cluster formation. Obstacles and possibleremedies to the current limitations are discussed.
| The dynamics of rich clusters of galaxies. II - The Perseus cluster
The dynamics of the Perseus cluster are analyzed using self-consistentequilibrium analytical models. Using existing data in the literatureplus new radial velocities reported here, composite surface density andvelocity dispersion profiles are derived. These profiles have beencompared with dynamical models described by Kent and Gunn (1982). Thebest fit suggest the presence of a significant degree of anisotropy inthe velocity distribution: galaxy orbits are constrained to pass withina radius of seven cluster radii, or 1.3 deg of the cluster center. ForHubble constant = 50, a core radius of 340 kpc 11 arcmin and a mass tovisual light ratio M/L = 300 are found. Using these results, X-rayobservations of the intracluster medium in Perseus are reanalyzed. Apreviously noted discrepancy between the observed temperature of the hotgas and the cluster velocity dispersion is reduced but not eliminated. Acooling accretion flow previously deduced to exist in this cluster isshown to extend to only about one-third of the cluster radius.
| Dynamics of the Perseus Cluster of Galaxies
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJ...168..321C&db_key=AST
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