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|Redshift-Distance Survey of Early-Type Galaxies: Circular-Aperture Photometry|
We present R-band CCD photometry for 1332 early-type galaxies, observedas part of the ENEAR survey of peculiar motions using early-typegalaxies in the nearby universe. Circular apertures are used to tracethe surface brightness profiles, which are then fitted by atwo-component bulge-disk model. From the fits, we obtain the structuralparameters required to estimate galaxy distances using theDn-σ and fundamental plane relations. We find thatabout 12% of the galaxies are well represented by a pure r1/4law, while 87% are best fitted by a two-component model. There are 356repeated observations of 257 galaxies obtained during different runsthat are used to derive statistical corrections and bring the data to acommon system. We also use these repeated observations to estimate ourinternal errors. The accuracy of our measurements are tested by thecomparison of 354 galaxies in common with other authors. Typical errorsin our measurements are 0.011 dex for logDn, 0.064 dex forlogre, 0.086 mag arcsec-2 for<μe>, and 0.09 for mRC,comparable to those estimated by other authors. The photometric datareported here represent one of the largest high-quality and uniformall-sky samples currently available for early-type galaxies in thenearby universe, especially suitable for peculiar motion studies.Based on observations at Cerro Tololo Inter-American Observatory (CTIO),National Optical Astronomy Observatory, which is operated by theAssociation of Universities for Research in Astronomy, Inc., undercooperative agreement with the National Science Foundation (NSF);European Southern Observatory (ESO); Fred Lawrence Whipple Observatory(FLWO); and the MDM Observatory on Kitt Peak.
|The far-ultraviolet emission of early-type galaxies|
We have assembled a UV-flux selected sample of 82 early-type galaxiesand collected additional information at other wavelengths. These dataconfirm a large spread of the UV-V color in the range 2 to 5. The spreadin UV-V is accompanied by a spread in B-V that is mainly attributed tothe range of morphological types and luminosities. A large fraction ofthe objects have red colors, UV-V = 4 +/- 0.4, corresponding to a weakUV-upturn as observed with IUE. If the current interpretation for the UVemission from early-type galaxies is applicable to our sample, the PAGB(Post-Asymptotic Giant Branch) tracks are the most common evolution pathfor the low-mass stars responsible for the UV emission. A small numberof very blue (UV-V < 1.4) objects have been found that can bereasonably interpreted as harbouring some low level of star formation.In contrast to a previous sample based on IUE observations, nocorrelation is found between the UV-V color and the Mg2spectral line index; possible explanations are reviewed. The potentialof a more extended UV survey like GALEX is briefly presented.
|Arcsecond Positions of UGC Galaxies|
We present accurate B1950 and J2000 positions for all confirmed galaxiesin the Uppsala General Catalog (UGC). The positions were measuredvisually from Digitized Sky Survey images with rms uncertaintiesσ<=[(1.2")2+(θ/100)2]1/2,where θ is the major-axis diameter. We compared each galaxymeasured with the original UGC description to ensure high reliability.The full position list is available in the electronic version only.
|Groups of galaxies. III. Some empirical characteristics.|
|Ultraviolet observations of galaxies with the FAUST experiment|
We have used the set of point sources detected by the Far UltravioletSpace Telescope (FAUST) instrument to identify galaxies and study thetotal galaxy flux in a 250 A wide band peaking at 1650 A. A sample of144 galaxies has been obtained after cross-reference with the RC3catalog, elimination of objects confused with stars and variouscorrections for the photometry. The UV-B color dispersion is found toincrease while the galaxies get redder from late to early types. Theirregular galaxies appear on average redder and the Sbc galaxies bluerthan indicated by the spectral energy distributions currently used forthe calculations of K-corrections. Various arguments lead us to make theassumption of a constant dust extinction within each galaxy. The UV fluxper unit area decreases on average from late to early type spirals. Wefind a weak correlation between the UV and far infra-red emission whilethe infra-red to UV flux ratio gets lower when galaxies get bluer (asmeasured by the UV to B flux ratio). The UV flux per unit areacorrelates with the HI gas surface density and the total gas surfacedensity when this quantity is available. The correlation with themolecular gas alone is weak. In the Virgo cluster, the UV flux per unitarea does not decrease in direct proportion to the HI deficiency. Galaxycounts per square degree and per magnitude interval have been obtainedat high-galactic latitudes. Combined with data at fainter magnitudes,they show a variation as a function of magnitude with a near-euclideanslope over a range of 8 magnitudes.
|The kinematics of the Virgo cluster revisited|
The paper updates the velocity data of Virgo cluster galaxies andreconsiders the kinematic structure of the Virgo cluster. New velocitiesare given for 144 galaxies listed in the Virgo Cluster Catalog (VCC).Improved velocities are given for another 131 VCC galaxies. The Virgocluster is disentangled from its surrounding clouds of galaxies, and thelikely members of each of these clouds are listed. The velocitydistribution of dwarf elliptical cluster members is found to be highlyasymmetric. This phenomenon is interpreted as evidence for the imminentmerging of two subclusters in the core region, which points to thedynamical youth of the Virgo cluster. The mean heliocentric velocity ofthe Virgo cluster is estimated at 1050 +/- 35 km/s.
|Continuum radio emission from Virgo galaxies|
The paper presents single-antenna measurements of radio emission from120 galaxies in the Virgo cluster at 2380 MHz using a 2.6 arc min beam(half-power beam width). It also presents interferometric measurementsat the same frequency for 48 galaxies with less than or equal to 1 arcsec resolution. The relative concentration of the radio emission forthese galaxies, particularly the emission from the galactic diskcompared with that from the nucleus is discussed. It is found that thedisk emission dominates in most cases. Some indications that the fluxconcentration is greater in elliptical and lenticular galaxies than itis in spirals are also found.
|The pattern of H I deficiency in the Virgo cluster|
A sample of 160 galaxies in the Virgo region, including 16 new 21-cmprofiles in the Virgo 5-degree core obtained with the 305-m Arecibotelescope, are examined to investigate the severe depletion ofinterstellar H I within spiral galaxies in the Virgo cluster core. Asimilar and non-Gaussian distribution is found for the distribution of HI deficiencies of both faint galaxies and brighter spirals, andpopulations of galaxies with normal abundances of interstellar H I, andthose of gas poor objects exhibiting a late-type morphology, are bothnoted. One-sixth of the sample within the Virgo 5-degree core have lostmore than 90 percent by mass of their original neutral hydrogen, andthree quarters of the galaxies found within 2.5 degrees of M87 are H Ipoor by more than a factor of three. The most deficient galaxies arealso found to be the ones with the smallest ratios of H I to opticaldisk size, and H I poor galaxies are redder than normal, indicating thatstar formation has been quenched.
|HI-observations of galaxies in the Virgo cluster of galaxies. I - The data|
New H I-data for a large number of bright galaxies inside the 10 degradius area of the Virgo cluster of galaxies have been obtained with the100 m radiotelescope at Effelsberg. A total of 234 galaxies was observedfor the first time. Among them, 53 have been detected providing newaccurate radial velocities. Data from the literature have been compiled.Together with the new data, they form a (nearly homogeneous) set of H Iobservations for more than 450 galaxies.
|Studies of the Virgo Cluster. II - A catalog of 2096 galaxies in the Virgo Cluster area.|
The present catalog of 2096 galaxies within an area of about 140 sq degapproximately centered on the Virgo cluster should be an essentiallycomplete listing of all certain and possible cluster members,independent of morphological type. Cluster membership is essentiallydecided by galaxy morphology; for giants and the rare class of highsurface brightness dwarfs, membership rests on velocity data. While 1277of the catalog entries are considered members of the Virgo cluster, 574are possible members and 245 appear to be background Zwicky galaxies.Major-to-minor axis ratios are given for all galaxies brighter than B(T)= 18, as well as for many fainter ones.
|A survey of galaxy redshifts. IV - The data|
The complete list of the best available radial velocities for the 2401galaxies in the merged Zwicky-Nilson catalog brighter than 14.5mz and with b (II) above +40 deg or below -30 deg ispresented. Almost 60 percent of the redshifts are from the CfA surveyand are accurate to typically 35 km/s.
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