The X-Ray Baldwin Effect
Abstract
Using the X-ray data of active galactic nuclei (type 1 Seyfert galaxies and quasars) obtained by the X-ray satellite Ginga, we have found that the equivalent width of the Fe K emission line at 6.4 keV, EW(Fe K), is inversely correlated with the X-ray luminosity in the 2-10 keV band. This inverse correlation is basically similar to the well-known relation known as the "Baldwin effect," which means that the equivalent width of the C IV λ1550 emission line is inversely correlated with the UV continuum luminosity (Baldwin 1977). Hence, we may call our finding "the X-ray Baldwin effect." The X-ray Baldwin effect is pronounced for type 1 Seyfert galaxies. The obtained correlation, EW(Fe K) is proportional to L_x_(2-10 keV)^-0.20+/-0.03, is quite similar to those of the original Baldwin effects for type 1 Seyfert galaxies and quasars, implying that the Fe K emission mainly comes from the broad-line regions or from the regions whose geometrical configurations are nearly the same as those of broad-line regions.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1993
- DOI:
- 10.1086/186948
- Bibcode:
- 1993ApJ...413L..15I
- Keywords:
-
- Active Galactic Nuclei;
- Quasars;
- Seyfert Galaxies;
- X Ray Spectra;
- X Rays;
- Continuous Spectra;
- Emission Spectra;
- Ginga Satellite;
- Spaceborne Astronomy;
- Spectral Line Width;
- Astrophysics;
- GALAXIES: SEYFERT;
- GALAXIES: QUASARS: EMISSION LINES;
- X-RAYS: GALAXIES