We report the results from an ASCA X-ray observation of the powerful broad-line radio galaxy 3C 109. The ASCA spectra confirm our earlier ROSAT detection of intrinsic X-ray absorption associated with the source. The absorbing material obscures a central engine of quasar-like luminosity. The luminosity is variable, having dropped by a factor of 2 since the ROSAT observations 4 years before. The ASCA data also provide evidence for a broad iron emission line from the source, with an intrinsic FWHM of ~120 000kms^-1. Interpreting the line as fluorescent emission from the inner parts of an accretion disc, we can constrain the inclination of the disc to be >35 deg, and the inner radius of the disc to be <70 Schwarzschild radii. Our results support unified schemes for active galaxies, and demonstrate a remarkable similarity between the X-ray properties of this powerful radio source and those of lower luminosity, Seyfert 1 galaxies.
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 1997
- GALAXIES: ACTIVE;
- GALAXIES: INDIVIDUAL: 3C 109;
- X-RAYS: GALAXIES;
- MNRAS in press. 7 pages, 5 figures in MNRAS LaTex style