Contents
Images
Upload your image
DSS Images Other Images
Related articles
HYPERLEDA. II. The homogenized HI data
After a compilation of HI data from 611 references and new observationsmade in Nançay, we produce a catalog of homogenized HI data for16781 galaxies. The homogenization is made using the EPIDEMIC methodfrom which all data are progressively converted into the adoptedstandard. The result is a catalog giving: 1) the logarithm of twice themaximum rotation velocity, log 2V_Msin i, converted to thesystem of Mathewson et al. (\cite{Mathewson1996}). This quantity isgiven without correction for inclination; 2) the HI magnitude,m21, (area of the 21-cm line width expressed in magnitude)converted to the flux system of Theureau et al. (\cite{Theureau1998});3) the HI velocity, V_HI, expressed with the optical definition (i.e.,using wavelengths instead frequencies). The typical uncertainties are:0.04 for log 2V_Msin i, 0.25 mag for m21 and 9 kms-1 for V_HI.Full Tables \ref{epidemicw}, \ref{epidemicw2}, \ref{epidemicf},\ref{epidemicf2} and Fig. \ref{profiles} are available in electronicform at http://www.edpsciences.org. Full Tables \ref{references},\ref{cataf}, \ref{newdata} and \ref{notes} are available in electronicform at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5)or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/412/57
| The Morphologies of Dwarf Markarian Galaxies
The morphologies of the 96 dwarf (M(B) -17m) galaxies in the Markariancatalog are determined from the digitized Schmidt plates obtained forthe construction of the Hubble Space Telescope Guide Star Catalog. Thefraction of double nucleus galaxies within the dwarf Markarian galaxiesis determined to be twice that found for all galaxies in the Markariancatalog. In addition to the 12 previously known cases, four definite andtwo probable galaxies with double nuclei are identified. The fraction ofdwarf Markarian galaxies with bright star forming regions is found to betwice that of Virgo cluster dwarf galaxies. No Elliptical galaxies arefound in the sample. Galaxies with blue compact dwarf and S0morphologies are more often found to contain unresolved regions of UVexcess emission. Dwarf Markarian galaxies with different morphologicalstructures and spectral classes are found to have similar FIRproperties.
| 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.
| The Southern Sky Redshift Survey
We report redshifts, magnitudes, and morphological classifications for5369 galaxies with m_B <= 15.5 and for 57 galaxies fainter than thislimit, in two regions covering a total of 1.70 sr in the southerncelestial hemisphere. The galaxy catalog is drawn primarily from thelist of nonstellar objects identified in the Hubble Space TelescopeGuide Star Catalog (GSC). The galaxies have positions accurate to ~1"and magnitudes with an rms scatter of ~0.3 mag. We compute magnitudes(m_SSRS2) from the relation between instrumental GSC magnitudes and thephotometry by Lauberts & Valentijn. From a comparison with CCDphotometry, we find that our system is homogeneous across the sky andcorresponds to magnitudes measured at the isophotal level ~26 magarcsec^-2. The precision of the radial velocities is ~40 km s^-1, andthe redshift survey is more than 99% complete to the m_SSRS2 = 15.5 maglimit. This sample is in the direction opposite that of the CfA2; incombination the two surveys provide an important database for studies ofthe properties of galaxies and their large-scale distribution in thenearby universe. Based on observations obtained at Cerro TololoInter-American Observatory, National Optical Astronomy Observatories,operated by the Association of Universities for Research in Astronomy,Inc., under cooperative agreement with the National Science Foundation;Complejo Astronomico El Leoncito, operated under agreement between theConsejo Nacional de Investigaciones Científicas de laRepública Argentina and the National Universities of La Plata,Córdoba, and San Juan; the European Southern Observatory, LaSilla, Chile, partially under the bilateral ESO-ObservatórioNacional agreement; Fred Lawrence Whipple Observatory;Laboratório Nacional de Astrofísica, Brazil; and the SouthAfrican Astronomical Observatory.
| 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.
| CCD calibration of the magnitude scale for the SSRS2 sample: The equatorial region
In this paper we continue our investigation on the isophotal nature,accuracy, and uniformity of the magnitude system adopted in the SouthernSky Redshift Survey extension (SSRS2). Extending our earlier work, weexamine galaxies in the equatorial region, primarily in the declinationrange delta greater than or equal to -17.5 deg and less than or equal to0 deg, over a large range of right ascension, covering the southern andnorthern Galactic caps. For this purpose, we have obtained CCD isophotalmagnitudes in the B and R bands for 265 galaxies of differentmorphological types. Using the larger sample we confirm our earlierclaim that the mSSRS2 magnitudes are very nearly themagnitude measured within the isophote muB = 26 mag/sqarcsec, with a dispersion of about 0.30 mag. The relative zero-pointoffset between our mSSRS2 magnitudes and the CCD photometryis -0.02 mag from all data we have obtained. However, we detect avariation of the zero-point across different regions of the sky of +/-0.10 mag for regions at large angular separations. We also estimate thatthe zero-point offset between the mSSRS2 and Zwicky systemsis relatively small (approximately 0.10 mag), which should allow us tocombine the data from the SSRS2 and the CfA2 Redshift Survey.
| The morphological catalogue of galaxies equatorial survey
We present 865 redshifts of galaxies located in the equatorial stripdelta between -17.5 deg and -2.5 deg in the right ascension rangebetween 20 h and 5 h. Redshifts have been obtained for the completesample of all 833 galaxies in the Morphological Catalog of Galaxies withmagnitudes brighter than m = 14.5 (corresponding approximately tom(Zwicky) = 15.0). This sample also includes three galaxies from othersources with more reliable magnitudes, satisfying this limit, and 29fainter galaxies, usually companions of the galaxies in the magnitudelimited sample. Our maps of a very large volume of nearby spacedemonstrate a variety of coherent large scale structures which includelarge voids, 20-50/h Mpc in diameter and large walls at least 70/h Mpcacross.
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Catalogs and designations:
|
INHABITED SKY
