Contents
Images
Upload your image
DSS Images Other Images
Related articles
The UZC-SSRS2 Group Catalog
We apply a friends-of-friends algorithm to the combined Updated ZwickyCatalog and Southern Sky Redshift Survey to construct a catalog of 1168groups of galaxies; 411 of these groups have five or more members withinthe redshift survey. The group catalog covers 4.69 sr, and all groupsexceed the number density contrast threshold, δρ/ρ=80. Wedemonstrate that the groups catalog is homogeneous across the twounderlying redshift surveys; the catalog of groups and their membersthus provides a basis for other statistical studies of the large-scaledistribution of groups and their physical properties. The medianphysical properties of the groups are similar to those for groupsderived from independent surveys, including the ESO Key Programme andthe Las Campanas Redshift Survey. We include tables of groups and theirmembers.
| High and Low Surface Brightness Galaxies in the Local Universe. V. Optical and H I Properties
Using optical spectra of the nuclei of 250 galaxies chosen from theAutomated Plate Measuring Facility (APM) survey of UK Schmidt plates, wederive synthetic B-V and V-R colors, estimates of reddening from Balmerdecrements, metallicity via oxygen abundance, and star formation ratefrom the Hα luminosity. We also present mass-to-light ratios andgas mass fractions from 21 cm H I measurements of 238 APM surveygalaxies, 101 of which also have optical spectra. This sample ofgalaxies spans a large range in surface brightness, from high surfacebrightness irregular galaxies down to the kind of low surface brightness(LSB) galaxies that are missing from most magnitude-limited catalogs.The generally blue global colors are best explained by a combination oflow metallicity and active star formation, primarily because of thetremendous scatter in metallicity versus B-V. Optical spectra show thepresence of G and K main-sequence stars in the nuclei of these galaxies,and the stellar mass-to-light ratios and gas mass fractions show thegalaxies as a whole to be gas-rich. LSB galaxies are most likely toexperience sporadic low levels of star formation over gigayeartimescales.
| Low Surface Brightness Galaxies in the Local Universe. I. The Catalog
Data are presented for 693 galaxies identified in a large new survey forlow surface brightness galaxies in the nearby universe (z <~ 0.1).The survey covers 786 square degrees centered on the equator, and itextends significantly the surface brightness range of galaxy surveys inwhich there are a substantial number of galaxies with redshifts. Thedata are derived from the Automated Plate Measuring machine scans ofsurvey plates from the UK Schmidt Telescope and from follow-upobservations at radio and optical wavelengths. Accurate positions, totalB magnitudes, surface brightness parameters, and angular sizes aretabulated for each galaxy. Radial velocities, optical luminosities, andneutral hydrogen masses are listed for a subset of the sample. Findingcharts are also presented for those objects having a large enoughangular size that the scans from survey plates provide somemorphological information. The selection function and the luminosityfunction that can be derived from the survey are discussed in twocompanion papers.
| An extragalactic database. I - The Catalogue of Principal Galaxies
The Catalogue of Principal Galaxies is described, which lists equatorialcoordinates (for the equinoxes 1950 and 2000) and cross-identificationsfor 73,197 galaxies. The 40,932 coordinates have standard deviationssmaller than 10 arcsec. A total of 131,601 names from the 38 most commonsources are listed. In addition, mean data for each object are givenwhen available: 49,102 morphological descriptions, 52,954 apparent majorand minor axes, 67,116 apparent magnitudes, 20,046 radial velocities and24,361 position angles. This information was used for facilitatingproper identification. Finally, distribution options are explained.
| Double galaxy investigations. I - Observations
Redshift information from 240 A/mm spectrograms is presented for 370double arcsec galaxy systems from the Karachentsev (1972) catalog,including all pairs in that catalog with separation less than 80 arcsec.An extensive error discussion utilizing internal and external (21 cm)comparisons provides calibration of systematic error and determines theuncertainty for a typical high weight optical redshift to be plus orminus 65 km/sec. Internal differential redshifts within single spectrausing common lines achieve accuracies of 18-30 km/sec, depending uponseparation, and are available for about 200 pairs. Extensive informationon emission and other properties is also provided.
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Catalogs and designations:
|
