Bowen Fluorescence in a Sample of Seyfert Nuclei
Abstract
We discuss new observations of the O III and N III Bowen fluorescence lines in a sample of two Seyfert 2 nuclei and six Seyfert 1 nuclei with relatively narrow permitted lines. Included are new measurements of O III λλ3133, 3444, which are the two strongest cascades produced in the Bowen process, and possible detections of O III λ3341, a secondary cascade expected to be produced following emission of a λ3133 photon. Our data cover a wide spectral range, from the atmospheric limit at ~ 3100 A out to redward of [S II] λλ6716, 6731. Measurements of the [S II] and [O III] lines are used to estimate densities for the program objects. Using the flux-calibrated spectra and the Bowen yields, together with the derived electron densities, we construct a model spherical Bowen-emitting region. This region, which has a derived radius of 1-10 pc, has a small filling factor (10^-7^ to 10^-3^). The clouds cover the central source, but are optically thin to the soft X-ray continuum emitted at the source. Many (~ 10^10^) clouds, of size, 1-1000 AU, inhabit the emitting region. The total required mass in clouds is ~ 100-10^6^ M_sun_.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- October 1990
- DOI:
- 10.1086/169244
- Bibcode:
- 1990ApJ...362...74S
- Keywords:
-
- Electron Photon Cascades;
- Galactic Nuclei;
- Line Spectra;
- Nitrogen Ions;
- Oxygen Spectra;
- Seyfert Galaxies;
- Binary Stars;
- Electron Density (Concentration);
- Neutron Stars;
- X Ray Sources;
- Astrophysics;
- ATOMIC PROCESSES;
- GALAXIES: NUCLEI;
- GALAXIES: SEYFERT;
- LINE FORMATION