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|Line-strength indices and velocity dispersions for 148 early-type galaxies in different environments|
We have derived high quality line-strength indices and velocitydispersions for a sample of 148 early-type galaxies in differentenvironments. The wavelength region covered by the observations (lambda=~ 4600 to 6600 Å) includes the Lick/IDS indices Hβ,Mg1, Mg2, Mgb, Fe5015, Fe5270, Fe5335, Fe5406,Fe5709, Fe5782, NaD, TiO1 and TiO2. The data areintended to address possible differences of the stellar populations ofearly-type galaxies in low- and high-density environments. This paperdescribes the sample properties, explains the data reduction andpresents the complete list of all the measurements. Most galaxies of thesample (85%) had no previous measurements of any Lick/IDS indices andfor 30% of the galaxies we present first-time determinations of theirvelocity dispersions. Special care is taken to identify galaxies withemission lines. We found that 62 per cent of the galaxies in the samplehave emission lines, as measured by the equivalent width of the [OIII]5007Å line, EW[OIII] > 0.3 Å. Tables 5 and 6 are onlyavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/ A+A/395/431. They are also available via ftp atftp.mpe.mpg.de in the directory people/dthomas/Beuing02 or via WWW atftp://ftp.mpe.mpg.de/people/dthomas/Beuing02.
|Background galaxies as reddening probes throughout the Magellanic Clouds|
We study the spectral properties in the range 3600 Å-6800 Åof the nuclear region of galaxies behind the Magellanic Clouds. Theradial velocities clarified the nature of the objects as backgroundgalaxies or extended objects belonging to the Clouds. For most galaxiesbehind the main bodies of the LMC and SMC, radial velocities weremeasured for the first time. In the present sample typical LMCbackground galaxies are nearby (4000 < V(km s-1) <6000), while SMC's are considerably more distant (10 000 < V(kms-1) < 20 000). We determine the reddening in each line ofsight by matching a reddening-free galaxy template with comparablestellar population. For the LMC main body we derive a combined Milky Wayand internal reddening value E(B-V)MW+i = 0.12 +/- 0.10,while for the SMC E(B-V)MW+i = 0.05 +/- 0.05. By subtractingMilky Way reddening values for galaxies projected onto the surroundingsof each Cloud, we estimate average internal reddening values DeltaE(B-V)i = 0.06 and 0.04, respectively for the main bodies ofthe LMC and SMC. The Clouds are optically thin, at least in thedirections of the studied background galaxies which are often difficultto be identified as such on ESO/SERC sky survey images. Nevertheless,more reddened zones may occur where it is difficult to identifygalaxies.
|Nearby Optical Galaxies: Selection of the Sample and Identification of Groups|
In this paper we describe the Nearby Optical Galaxy (NOG) sample, whichis a complete, distance-limited (cz<=6000 km s-1) andmagnitude-limited (B<=14) sample of ~7000 optical galaxies. Thesample covers 2/3 (8.27 sr) of the sky (|b|>20deg) andappears to have a good completeness in redshift (97%). We select thesample on the basis of homogenized corrected total blue magnitudes inorder to minimize systematic effects in galaxy sampling. We identify thegroups in this sample by means of both the hierarchical and thepercolation ``friends-of-friends'' methods. The resulting catalogs ofloose groups appear to be similar and are among the largest catalogs ofgroups currently available. Most of the NOG galaxies (~60%) are found tobe members of galaxy pairs (~580 pairs for a total of ~15% of objects)or groups with at least three members (~500 groups for a total of ~45%of objects). About 40% of galaxies are left ungrouped (field galaxies).We illustrate the main features of the NOG galaxy distribution. Comparedto previous optical and IRAS galaxy samples, the NOG provides a densersampling of the galaxy distribution in the nearby universe. Given itslarge sky coverage, the identification of groups, and its high-densitysampling, the NOG is suited to the analysis of the galaxy density fieldof the nearby universe, especially on small scales.
|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.
|Candidates for a southern extension of the Karachentsev catalogue of isolated pairs of galaxies.|
|UBVRI photoelectric photometry of bright southern early-type galaxies|
UBVRI multi-aperture photometry of 207 bright southern galaxies and of72 objects of an additional list is presented. These observations weremade for obtaining the magnitude scale zero-point as an accuratedetermination of the sky background for a two-dimensional photometryprogram concerning these galaxies. We have also inferred the asymptoticmagnitudes, color indices and effective apertures of these objects. Ourresults are in good agreement with those of others authors.
|Observational data for the kinematics of the local universe. I - Radial velocity measurements|
The study of the local velocity field requires the use of a very largesample to describe as accurately as possible some prominent features ofthe local kinematics. The problem of collecting a large sample is mademore difficult because of the Malmquist bias which plagues distancedeterminations. The present program aims at determining bias-freedistances for a complete sample in order to study the local velocityfield. The present paper gives 303 preliminary optical and radioredshifts measured for this program at ESO, OHP and NancayObservatories.
|Simulated aperture-photometry on CCD-frames for 67 southern galaxies in B and R|
As part of a large project to calibrate all the Schmidt plates of theESO Quick blue and the red survey, CCD-photometry in B and R has beenobtained for galaxies on 67 different survey fields. On these framessynthetic-aperture photometry is applied in order to present the data ina way which makes the comparison with photographic photometry easy.
|Southern Galaxy Catalogue.|
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