IUE observations of high-redshift quasars.
Abstract
The authors have measured the continuum energy distributions of nine high-redshift quasars (1.0 ≤ z ≤ 2.2) with the IUE and the Palomar 5 m multichannel spectrophotometer. Generally, the spectral energy distributions steepen at a rest wavelength of about 1200 Å, from a power law, in the optical, of spectral index α ≈ -0.5, to a spectral index of -3 to -5 shortward of 1200 Å. An extensive discussion of the physical causes of this spectral steepening is presented. Six of the spectra exhibit a total of nine optically thick Lyman limit discontinuities with zabs very low zem. Eight out of nine of the systems surveyed have associated Mg II or C IV doublets, with physical parameters consistent with the hypothesis that the absorbing material is associated with a galactic halo or disk.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1984
- DOI:
- 10.1086/162076
- Bibcode:
- 1984ApJ...281...76B
- Keywords:
-
- Iue;
- Quasars;
- Spectral Energy Distribution;
- Ultraviolet Spectra;
- Astronomical Spectroscopy;
- Continuous Spectra;
- Interstellar Extinction;
- Line Of Sight;
- Lyman Spectra;
- Metallicity;
- Opacity;
- Spectrophotometry;
- Astrophysics