Kinematics and Structure of Radio Ellipticals.
Abstract
Available from UMI in association with The British Library. Kinematic and structural properties of intermediate -power radio elliptical galaxies are investigated. Emphasis is placed on determining whether or not there is a coupling between the stellar populations of the host galaxies and their radio emission. The sample of about 90 southern radio galaxies, of Ekers et al. (1986), is used as a basis for this study. Optical photometry is derived from CCD images. Long-slit spectroscopic observations are obtained for a subset of 33 radio ellipticals, 14 of which have sufficient counts to give stellar rotation curves and velocity dispersion profiles as well as central dispersions. A study is made of the relative orientations of the apparent radio and optical axes of these radio galaxies. The observed distribution of relative orientations is compared with the predictions made from Monte-Carlo simulations, which take into account the projection effects of different host galaxy shapes. The stellar kinematics of the radio ellipticals are compared with those of radio-quiet ellipticals. Their rotation properties are found to be comparable. Their distribution in the luminosity - velocity dispersion plane is systematically offset from that defined by normal ellipticals. This is shown to be caused by the radio selection criteria. From these studies there is no indication that the radio structures know about the extended stellar populations. The neighbourhoods of these radio galaxies are investigated. Redshifts are obtained for some of their apparent companion galaxies. The number of real associations of the companions with radio galaxies is found to be high (~ 90%). Their distribution of relative velocities shows that these companions are not likely to merge with the radio galaxies.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1987
- Bibcode:
- 1987PhDT........20S
- Keywords:
-
- Physics: Astronomy and Astrophysics;
- Elliptical Galaxies;
- Kinematics;
- Radio Emission;
- Radio Galaxies;
- Stellar Rotation;
- Computerized Simulation;
- Monte Carlo Method;
- Red Shift;
- Stellar Luminosity;
- Space Radiation