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Redshift-Distance Survey of Early-Type Galaxies: Spectroscopic Data
We present central velocity dispersions and Mg2 line indicesfor an all-sky sample of ~1178 elliptical and S0 galaxies, of which 984had no previous measures. This sample contains the largest set ofhomogeneous spectroscopic data for a uniform sample of ellipticalgalaxies in the nearby universe. These galaxies were observed as part ofthe ENEAR project, designed to study the peculiar motions and internalproperties of the local early-type galaxies. Using 523 repeatedobservations of 317 galaxies obtained during different runs, the dataare brought to a common zero point. These multiple observations, takenduring the many runs and different instrumental setups employed for thisproject, are used to derive statistical corrections to the data and arefound to be relatively small, typically <~5% of the velocitydispersion and 0.01 mag in the Mg2 line strength. Typicalerrors are about 8% in velocity dispersion and 0.01 mag inMg2, in good agreement with values published elsewhere.
| 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.
| Hubble constant from sosie galaxies and HIPPARCOS geometrical calibration
New distances, larger than previous ones, have been obtained for M 31and M 81 based on the geometrical zero-point of the CepheidPeriod-luminosity relation provided by the HIPPARCOS satellite. Bycombining them with independent determinations we define reasonableranges for the distances of these important calibrating galaxies. Onthis basis, we determine the Hubble constant from the method of sosies(look-alike) galaxies, galaxies having the same characteristics than thecalibrators. The method is quite secure because it is purelydifferential and it does not depend on any assumption (apart from thenatural one that two sosies galaxies have similar absoluteluminosities). Nevertheless, the Malmquist bias has to be taken intoaccount. The observations behave exactly as predicted from theanalytical formulation of the bias. Thus, rejecting galaxies which areaffected by the Malmquist bias we derive the Hubble constant: H_o = 60+/- 10 (external) km.s^{-1}.Mpc^{-1} If we strictly use the calibrationobtained with HIPPARCOS and if the bias found in the Period-LuminosityRelation is considered, the Hubble constant is smaller than this (~ 55km.s(-1}.Mpc({-1)) ). This gives arguments in favour of thelong-distance scale. We briefly discuss possible improvements aiming atstill reducing the uncertainty.
| Kinematics of the local universe. III. Neutral hydrogen observations of southern galaxies.
This paper is the third one in a series dedicated to the study of thekinematics of the local universe. It gives 52 new 21-cm neutral hydrogenmeasurements, made with the 64-m Parkes radio telescope. These newmeasurements are used to built a complete sample of 5,219 galaxies with21-cm line widths, radial velocity and apparent diameter. This sample iscomplete down to a diameter limit of 1.6 arcmin.
| Candidates for a southern extension of the Karachentsev catalogue of isolated pairs of galaxies.
Not Available
| 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.
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