We detected small (~ 1 '') disks and lanes of dust and emission-gas in a complete sample of 21 nearby (D < 70h-1 Mpc) radio-loud elliptical galaxies using HST/WFPC2 broad- and narrowband filters. Disks are aligned with the galaxy major axis and have outlines which closely resemble ellipses, while lanes are misaligned warped filaments. We discuss the various possible origins for the dust and gas and its orientation relative to the radio jet. Several nuclei show unresolved nuclear blue emission. We argue this emission is non-thermal in nature which can explain correlations with radio and optical emission-line luminosities. We make a comparison between the central stellar and ISM properties of this sample and those of quiescent early-type galaxies. First results of a HST/STIS follow-up study of the sample are presented. The emission-line kinematics are derived from three adjacent slits along the major axis. The inferred two-dimensional kinematics are used to put limits on the mass of the central black hole. Line ratios in the wavelength range 3000 Å - 10000 Å are obtained for a few targets to constrain the ionization mechanism: shock- or photo-ionization.
Galaxies and their Constituents at the Highest Angular Resolutions
- Pub Date:
- January 2001
- 4 pages. Contributed talk at IAU Symposium 205: Galaxies and their Constituents at the Highest Angular Resolutions, Manchester UK, August 2000. Proceedings to be published by ASP, edited by R. Schilizzi, S. Vogel, F. Paresce, M. Elvis