PG 1700+518 : a low-redshift, broad absorption line QSO.
Abstract
The first high-resolution optical spectra and lower resolution UV spectra of PG 1700 + 518, the only known broad-absorption-line (BAL) QSO at low emission redshift (0.288) are presented. The optical data were obtained with the Isaac Newton Telescope on the island of La Palma and the UV data with the International Ultraviolet Explorer satellite. The outstanding feature of the optical spectrum is a strong, broad Mg II absorption trough, detached from the Mg II emission line and indicative of ejection velocities of between 7000 and 18,000 km/s. Also detected were narrow (FWHM = 350 km/s) Mg II absorption lines at absolute z = 0.2698, which are probably related to the mass ejection phenomenon. It is concluded that the emission-line spectrum is similar to that of other low-redshift QSOs although there are some obvious differences from typical BAL QSOs, most notably in the unusually low level of ionization of both emission-line and broad absorption line gas.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1985
- DOI:
- 10.1086/184512
- Bibcode:
- 1985ApJ...294L..73P
- Keywords:
-
- Absorption Spectra;
- Galactic Nuclei;
- Quasars;
- Red Shift;
- Iue;
- Line Spectra;
- Magnesium;
- Ultraviolet Spectra;
- Visible Spectrum;
- Astrophysics