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|The Dynamics of Poor Systems of Galaxies|
We assemble and observe a sample of poor galaxy systems that is suitablefor testing N-body simulations of hierarchical clustering and otherdynamical halo models. We (1) determine the parameters of the densityprofile rho(r) and the velocity dispersion profile sigma_p(R), (2)separate emission-line galaxies from absorption-line galaxies, examiningthe model parameters and as a function of spectroscopic type, and (3)for the best-behaved subsample, constrain the velocity anisotropyparameter, beta, which determines the shapes of the galaxy orbits. Oursample consists of 20 systems, 12 of which have extended X-ray emissionin the ROSAT All-Sky Survey. We measure the 877 optical spectra ofgalaxies brighter than m_R~15.4 within 1.5 h^-1 Mpc of the systemcenters (we take H_0=100 h km s^-1 Mpc^-1). Thus, we sample the systemmembership to a radius typically three times larger than other recentoptical group surveys. The average system population is 30 galaxies, andthe average line-of-sight velocity dispersion is ~300 km s^-1. TheNavarro, Frenk, & White universal profile and the Hernquist modelboth provide good descriptions of the spatial data. In most cases anisothermal sphere is ruled out. Systems with declining sigma_p(R) arewell-matched by theoretical profiles in which the star-forming galaxieshave predominantly radial orbits (beta>0) many of these galaxies areprobably falling in for the first time. There is significant evidencefor spatial segregation of the spectroscopic classes regardless ofsigma_p(R).
|Dynamics of cD Clusters of Galaxies. III. Redshift Data for 11 Abell Clusters|
We present the final observational data for a spectroscopic study of asample of cD galaxy clusters. The goal of this program has been to studythe dynamics of the clusters, with emphasis on determining the natureand frequency of peculiar-velocity cD galaxies. In this paper we presentredshifts for 762 galaxies in the fields of the rich Abell clustersA779, A1691, A1749, A1767, A1837, A1927, A2067, A2079, A2089, A2199, andA2666. We also present preliminary dynamical properties for theseclusters using our measured redshifts.
|Total magnitude, radius, colour indices, colour gradients and photometric type of galaxies|
We present a catalogue of aperture photometry of galaxies, in UBVRI,assembled from three different origins: (i) an update of the catalogueof Buta et al. (1995) (ii) published photometric profiles and (iii)aperture photometry performed on CCD images. We explored different setsof growth curves to fit these data: (i) The Sersic law, (ii) The net ofgrowth curves used for the preparation of the RC3 and (iii) A linearinterpolation between the de Vaucouleurs (r(1/4) ) and exponential laws.Finally we adopted the latter solution. Fitting these growth curves, wederive (1) the total magnitude, (2) the effective radius, (3) the colourindices and (4) gradients and (5) the photometric type of 5169 galaxies.The photometric type is defined to statistically match the revisedmorphologic type and parametrizes the shape of the growth curve. It iscoded from -9, for very concentrated galaxies, to +10, for diffusegalaxies. Based in part on observations collected at the Haute-ProvenceObservatory.
|21 CM H1 Line Spectra of Galaxies in Nearby Clusters|
A compilation of HI line fluxes, systemic velocities and line widths ispresented for \Ndet detected galaxies, mostly in the vicinities of 30nearby rich clusters out to a redshift of z ~ .04, specifically for usein applications of the Tully-Fisher distance method. New 21 cm HI lineprofiles have been obtained for ~ 500 galaxies in 27 Abell clustersvisible from Arecibo. Upper limits are also presented for \Nnod galaxiesfor which HI emission was not detected. In order to provide ahomogeneous line width determination optimized for Tully-Fisher studies,these new data are supplemented by the reanalysis of previouslypublished spectra obtained both at Arecibo and Green Bank that areavailable in a digital archive. Corrections for instrumental broadening,smoothing, signal-to-noise and profile shape are applied, and anestimate of the error on the width is given. When corrected forturbulent broadening and viewing angle, the corrected velocity widthspresented here will provide the appropriate line width parameter neededto derive distances via the Tully-Fisher relation.
|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.
|The CfA Redshift Survey: Data for the NGP +36 Zone|
We have assembled redshifts for a complete sample of 719 galaxies withm_zw_ <= 15.5 in the declination range 32.5^deg^ <= δ <=38.5^deg^ and right ascension range 8^h^ <= α <= 17^h^. Wehave determined morphological types for all galaxies in the magnitudelimited sample by direct inspection of the POSS-O plates. 576 of theredshifts are measurements from Mount Hopkins, and 405 are newredshifts. We also include new redshifts for 77 fainter galaxies in thesame strip.
|The kinematics of Abell clusters|
Velocity histograms, galaxy positions, and velocity dispersions arepresented for 69 nearby Abell clusters. The shape of the cumulativedistribution for R = 1 or more clusters does not match the predictionsof standard CDM models for any biasing parameter b. The only modelsconsistent with the median and maximum dispersions of the sample arethose of b about 1.6-2.0 and in which clusters are identified in threedimensions. Velocity dispersions of high-redshift systems appearfundamentally different from those of nearby clusters. The mediandispersion of the subset of 25 cD clusters is similar to that of non-cDsystems. A substantial fraction of the cD galaxies have velocitiessignificantly different from the mean of their parent clusters. Three ofthese have 4 s or more measured redshifts. These last two resultssuggest that the formation of cD galaxies is dominated by the local,rather than global, cluster environment.
|Radio and optical observations of 9 nearby Abell clusters - A262, A347, A569, A576, A779, A1213, A1228, A2162, A2666|
A survey is made of 61 Abell clusters included in the HEAO-2 satelliteobserving program at 1.4 GHz. Data are presented on the nine clusters ofdistance class 1 and 2. With a view to establishing galaxy morphologiesand extending the sample of the galaxies with known velocities, platesand spectra are obtained with a 152-cm telescope. The bivariate radioluminosity function of the cluster galaxies is determined for the threemorphological types, E, SO, and S plus Irr, dividing these into threedifferent classes of absolute optical magnitude. The radio luminosityfunctions of E and SO galaxies in present clusters do not differ fromthose of E and SO galaxies in clusters having higher richness. Someevidence exists that spiral galaxies in clusters have a lowerprobability of being radio sources than field ones. Also included is abrief discussion of the sizes of cluster radio sources and thecorrelation between radio emission and the presence of emission linesfrom a galaxy.
|Photographs of nebulae with the 60-inch reflector 1911-1916.|
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