Kinematic properties of gas and stars in 20 disc galaxies ^*,**

¹ Instituto Astrofísico de Canarias, Calle Via Lactea s/n, 38200 La Laguna, Spain
² Guest investigator of the UK Astronomy Data Centre
³ Osservatorio Astrofisico di Asiago, Dipartimento di Astronomia, Università di Padova, via dell'Osservatorio 8, 36012 Asiago, Italy
⁴ Vatican Observatory, University of Arizona, Tucson, AZ 85721, USA
⁵ Institut für Astronomie, Universität Wien, Türkenschanzstrasse 17, 1180 Wien, Austria
⁶ Dipartimento di Astronomia, Università di Padova, vicolo dell'Osservatorio 5, 35122 Padova, Italy

Corresponding author: J. C. Vega Beltrán, jvega@ll.iac.es

Received: 21 December 2000
Accepted: 23 April 2001

Abstract

Ionized gas and stellar kinematical parameters have been measured along the major axis of 20 nearby disc galaxies. We discuss the properties of each sample galaxy, distinguishing between those characterized by regular or peculiar kinematics. In early-type disc galaxies, ionized gas tends to rotate faster than stars and to have a lower velocity dispersion ( and ß), whereas in late-type spirals, gas and stars show almost the same rotation velocities and velocity dispersions ( and ß). Incorporating the early-type disc galaxies studied by Bertola et al. (1995), Fisher (1997) and Corsini et al. (1999), we have compiled a sample of some 40 galaxies for which the major-axis radial profiles of both the stellar and gaseous components have been measured. The value of ßmeasured at turns out to be strongly correlated with the galaxy morphological type, while is not and sometimes takes values above the range expected from thermal motions or small-scale turbulence.