Upload your image
DSS Images Other Images
Submit a new article
|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.
|Kinematics of the local universe. VII. New 21-cm line measurements of 2112 galaxies|
This paper presents 2112 new 21-cm neutral hydrogen line measurementscarried out with the meridian transit Nan\c cay radiotelescope. Amongthese data we give also 213 new radial velocities which complement thoselisted in three previous papers of this series. These new measurements,together with the HI data collected in LEDA, put to 6 700 the number ofgalaxies with 21-cm line width, radial velocity, and apparent diameterin the so-called KLUN sample. Figure 5 and Appendices A and B forcorresponding comments are available in electronic form at thehttp://www.edpsciences.com
|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.
|A catalogue of spatially resolved kinematics of galaxies: Bibliography|
We present a catalogue of galaxies for which spatially resolved data ontheir internal kinematics have been published; there is no a priorirestriction regarding their morphological type. The catalogue lists thereferences to the articles where the data are published, as well as acoded description of these data: observed emission or absorption lines,velocity or velocity dispersion, radial profile or 2D field, positionangle. Tables 1, 2, and 3 are proposed in electronic form only, and areavailable from the CDS, via anonymous ftp to cdsarc.u-strasbg.fr (to220.127.116.11) or via http://cdsweb.u-strasbg.fr/Abstract.html
|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 fundamental plane of early-type galaxies: stellar populations and mass-to-light ratio.|
We analyse the residuals to the fundamental plane (FP) of ellipticalgalaxies as a function of stellar-population indicators; these are basedon the line-strength parameter Mg_2_ and on UBVRI broad-band colors, andare partly derived from new observations. The effect of the stellarpopulations accounts for approximately half the observed variation ofthe mass-to-light ratio responsible for the FP tilt. The residual tiltcan be explained by the contribution of two additional effects: thedependence of the rotational support, and possibly that of the spatialstructure, on the luminosity. We conclude to a constancy of thedynamical-to-stellar mass ratio. This probably extends to globularclusters as well, but the dominant factor would be here the luminositydependence of the structure rather than that of the stellar population.This result also implies a constancy of the fraction of dark matter overall the scalelength covered by stellar systems. Our compilation ofinternal stellar kinematics of galaxies is appended.
|A comparative study of morphological classifications of APM galaxies|
We investigate the consistency of visual morphological classificationsof galaxies by comparing classifications for 831 galaxies from sixindependent observers. The galaxies were classified on laser print copyimages or on computer screen using scans made with the Automated PlateMeasuring (APM) machine. Classifications are compared using the RevisedHubble numerical type index T. We find that individual observers agreewith one another with rms combined dispersions of between 1.3 and 2.3type units, typically about 1.8 units. The dispersions tend to decreaseslightly with increasing angular diameter and, in some cases, withincreasing axial ratio (b/a). The agreement between independentobservers is reasonably good but the scatter is non-negligible. In spiteof the scatter, the Revised Hubble T system can be used to train anautomated galaxy classifier, e.g. an artificial neural network, tohandle the large number of galaxy images that are being compiled in theAPM and other surveys.
|Angular Momentum Loss During The Formation of Elliptical Galaxies|
|Observational Data for the Kinematics of the Local Universe - Part Two - Second Set of Radial Velocity Measurements|
This paper is the second one in a series dedicated to the study of thekinematics of the local universe. It gives 361 new optical and radioredshifts measured at ESO, OHP and Nancay Observatories.
|Redshift observations in the Hydra-Centaurus region|
The paper reports 406 redshifts for galaxies in the northern galactichemisphere, south of delta = 0 deg. A substantial fraction of theobserved galaxies are located in the equatorial zone between deltavalues of -17.5 and 0 deg. By combining these new data with thoseavailable in the literature, it is possible to extend the original CfAredshift survey of galaxies brighter than m(B(0)) = 14.5 to b = 30 deg,south of delta = 0. New data taken at lower galactic latitudes alsocontribute to the existing surveys of the Hydra-Centaurus complex.
|The role played by rotation and random motions in elliptical galaxies|
The observable kinematical quantities (rotation velocity and velocitydispersion) of elliptical galaxies are affected, among other things, bythe integration of the light along the line of sight. We present amethod to spatially deproject the rotation velocity curve and thevelocity dispersion profile. The application to a sample of 54ellipticals shows that, as is it widely recognized, the total kineticenergy originates mainly from the random motions, and that there is nocorrelation between rotation and velocity dispersion. If the correctionwith respect to the line-of-sight integration is taken into account, thecorrelation between the total absolute magnitude and the rotationparameter log(V/sigma)* turns out to be rather weak, while boxy anddisky ellipticals appear to be separated both in the (T(V), T-sigma)plane and in the (M(B),log(V/sigma)*) plane, thus confirming theexistence of different dynamical properties between these two classes ofobjects.
|New observations and a photographic atlas of polar-ring galaxies|
A photographic atlas of polar-ring galaxies and related objects ispresented. The atlas includes kinematically confirmed polar-ringgalaxies (category A), good condidates based on their morphologicalappearance (category B), possible candidates (category C), and possiblyrelated objects (category D). New photometric and kinematic observationsare reported for several galaxies in the catalog, including observationsthat show that UGC 7576 and UGC 9796 ( = II ZW 73) are S0 galaxies withpolar rings. Roughly 0.5 percent of all nearby S0 galaxies appear tohave polar rings. When corrected for various selection effects (e.g.,nonoptimal viewing orientation, possible dimming, or limited lifetime ofthe ring) the percentage increases to about 5 percent of S0 galaxieswhich have, or have had a polar ring.
|An extended galaxy redshift survey. I - The catalogue|
Redshifts and blue magnitudes are presented for a sample of 264 'field'galaxies virtually complete to a limiting magnitude of 16.80 mag. Thegalaxies were selected by sampling one galaxy in every three in order ofapparent magnitude on each of nine high-latitude UK Schmidt (UKST)fields. The spectral data came from observations with the 1.9-mtelescope at the South African Astronomical Observatory (SAAO), and theresulting radial velocities have a precision of 130 + or - km/s. Thissurvey augments substantially the Durham/AAT redshift survey. Theobservational techniques and reduction procedures are discussed.
|Counter-rotation in dust-lane ellipticals and the implications for accretion events in galaxies|
Decoupling of angular momenta of gas and stars in elliptical galaxiesconstitutes evidence for the acquisition of external material by thesegalaxies later in their history. New observations on four major-axisdust-lane ellipticals Anon 1029-459, NGC3528, NGC4370, and NGC5745, arepresented. In the first two of these, counterrotation of gas and starsis observed, whereas the two components are corotating in NGC4370 andNGC5745; these results are consistent with the acquisition hypothesis.The same accretion events occur also in S0 galaxies, where they giverise to polar rings or to counter- and corotating as in the equatorialplane. As dynamic decoupling in these latter galaxies appears common, itis suggested that in all S0s with extended emission lines the gas is ofexternal origin.
|A study of major-axis dust-lane ellipticals|
Kinematical and photometric observations of four early-type galaxieswith dust lanes along the major axes are presented. They are Anon1029-459, NGC 3528, 4370 and 5745. For Anon 1029-459 radio observationsare also presented. All the systems but NGC 4370 show relatively highstellar rotational velocities similar to those observed in SOs. The dustlanes in Anon 1029-459 and NGC 5745 are warped, suggesting that they arerelatively young. There are contradictory indications that these systemsare elliptical galaxies. The class of major-axis dust-lane ellipticalsis not yet as well defined as the class of minor-axis dust-lanegalaxies.
|Extragalactic dust. II - Far-infrared properties of early-type galaxies with dust lanes|
The far-infrared emission from some early-type galaxies with dust lanesindicates that star formation is taking place there. The ultravioletradiation from newly formed stars heats the dust to temperatures higherthan expected for H I regions illuminated by the integrated flux of theentire galaxy. Parallels with polar ring galaxies are drawn and anevolutionary scheme from dark lane to polar ring galaxy is suggested.
|Properties of elliptical galaxies with dust lanes|
The new galactic class of elliptical galaxies with dust lanes ischaracterized by an elliptical stellar body crossed along the minor axisby a dust lane. Ninety objects are presently listed as dust laneellipticals. In this paper, the morphological, statistical, kinematical,and photometric properties of these galaxies are described. The natureof the warps seen in the dust lanes in some of the galaxies isaddressed.
|The nuclear activity of interacting galaxies|
A search for active galactic nuclei among interacting galaxies isreported. A sample of 167 systems of interacting and asymmetric galaxieswas observed spectrophotometrically in the spectral range 4700-7100 A.The results are compared with a sample of isolated galaxies. It is foundthat (1) there are no Seyfert nuclei in elliptical or dwarf irregulargalaxies of the sample; (2) there is an excess of Seyfert nuclei amonginteracting spirals, but it is only at the 90 percent confidence level;(3) this excess becomes statistically significant (98 percent) when onlystrongly interacting spirals are included (four new Seyfert nuclei arepresented); (4) in the subgroup of galaxies with extreme tidaldistortions, no Seyfert nuclei were found.
|A catalog of dusty elliptical galaxies|
A catalog of about 100 dusty elliptical galaxies and some relatedobjects is presented. A morphological classification system is proposed,and the observed dust lane characteristics of some of the individualgalaxies are described. The properties of the galaxies are discussed,including the distribution of morphological types, their radioproperties, radio source orientation, neutral hydrogen, kinematics anddynamics, and relationship to other types of peculiar galaxies.
|Early-type /discless/ galaxies with dust lanes|
A comprehensive, homogeneous sample of 40 optically selected dust-lanegalaxies, which exhibit no obvious associated luminous disks, ispresented along with a preliminary discussion of its properties. Adearth of such galaxies in the north is attributed to the poorerresolution of the Palomar Sky Survey relative to the Southern SkySurvey, which is the source materiaal in the south. It is inferred thatthere may not be a comparably large population of galaxies with dustlanes closely confined to their central regions. The orientation of thedust lanes is varied, but the majority occurs impartially on the majoror minor axes of the light distribution, with a substantial minority ofskew cases with the dust at an intermediate angle. Observed propertiesof the galaxies are summarized, and it is suggested that the propertiesare best attributed to the accretion of cool material at a fairly recentepoch (less than a few x 10 to the 9th yr ago), and that subsequentevolution of this material can explain the observed distribution of dustlane orientation. It is thought that a significant number of early-typegalaxies are prolate in form.
|Atlas of interacting galaxies, Part. II and the concept of fragmentation of galaxies.|
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977A&AS...28....1V&db_key=AST
Submit a new link
Member of following groups:
Observation and Astrometry data
Catalogs and designations: