An optical study of the giant radio galaxy NGC 1316 (Fornax A).
Abstract
Photographic, photoelectric and optical spectroscopic observations of the giant radio galaxy NGC 1316 (Fornax A) are presented. Direct photographic plates, photoelectric surface brightness and color profiles and long-slit spectrograms were obtained using the 0.6-, 0.9-, 1.5- and 4-m telescopes at Cerro Tololo. The observations are interpreted to indicate that NGC 1316 is a typical Morgan type D galaxy, with an elliptical-like spheroid embedded in an extensive envelope, no exponential disk brighter than 26 mag/sq arcsec, a small core radius and probably located in a poor cluster of galaxies beyond the Fornax cluster. The presence of an inclined gas disk in the galaxy is attributed to a recent infall, and observations of loops, ripples and a sharp boundary in the spheroid and envelope are explained by the infall of one or possibly more external galaxies, which lead to past radio outbursts. The presence of two dust lanes that spiral directly into the nucleus is suggested to indicate that fueling from the disk continues and further outbursts are expected. The companion barred galaxy NGC 1317 is also briefly described.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1980
- DOI:
- 10.1086/157870
- Bibcode:
- 1980ApJ...237..303S
- Keywords:
-
- Astronomical Photography;
- Astronomical Spectroscopy;
- Optical Emission Spectroscopy;
- Radio Galaxies;
- Brightness;
- Cosmic Dust;
- Ionized Gases;
- Light (Visible Radiation);
- Photoelectric Emission;
- Photographic Plates;
- Radii;
- Spectrograms;
- Spectrum Analysis;
- Stellar Evolution;
- Surface Properties;
- Astrophysics