Spectrophotometry of Seyfert 1 galaxies.
Abstract
Relative emission-line intensities measured from image-tube/image-dissector spectral scans performed with a resolution of approximately 10 A are presented for 36 Seyfert 1 galaxies. The emission-line intensities are linked to the continuum by measuring the equivalent width of H-beta, the relative intensities for the Seyfert 1 galaxies are compared with those for five broad-line radio galaxies, and each Seyfert is classified into one of four groups on the basis of the appearance of its H-beta profile. It is shown that the broad-line radio galaxies generally have larger H-alpha/H-beta ratios and steeper Balmer gradients than the Seyferts, that the He I 5876-A and He II 4686-A lines in the Seyferts have widths comparable to those of the H I lines, and that the He abundances are approximately normal in most Seyfert 1 and broad-line radio galaxies. Nearly every Seyfert is found to have measurable Fe II emission, but a wide intensity range is observed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1977
- DOI:
- 10.1086/155407
- Bibcode:
- 1977ApJ...215..733O
- Keywords:
-
- Emission Spectra;
- H Lines;
- Radio Galaxies;
- Seyfert Galaxies;
- Spectral Line Width;
- Spectrophotometry;
- Abundance;
- Astronomical Photometry;
- Astronomical Spectroscopy;
- H Alpha Line;
- H Beta Line;
- Helium;
- Radio Spectra;
- Tables (Data);
- Astrophysics