A High Signal-to-Noise Ratio Composite Quasar Spectrum
Abstract
We present a very high signal-to-noise ratio (S/N ~ 400) composite spectrum of the rest-frame ultraviolet and optical region of high luminosity quasars. The spectrum is derived from 718 individual spectra obtained as part of the Large Bright Quasar Survey. The moderate resolution, <~ 4 A, and high signal-to-noise ratio allow numerous weak emission features to be identified. Of particular note is the large equivalent-width of the Fe II emission in the rest-frame ultraviolet and the blue continuum slope of the composite. The primary aim of this paper is to provide a reference spectrum for use in line identifications, and a series of large-scale representations of the composite spectrum are shown. We also present a measure of the standard deviation of the individual quasar spectra from the composite spectrum.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1991
- DOI:
- 10.1086/170066
- Bibcode:
- 1991ApJ...373..465F
- Keywords:
-
- Astronomical Spectroscopy;
- Emission Spectra;
- Quasars;
- Signal To Noise Ratios;
- Stellar Luminosity;
- Iron;
- Line Spectra;
- Red Shift;
- Spectral Resolution;
- Ultraviolet Spectra;
- Visible Spectrum;
- Astrophysics;
- LINE IDENTIFICATIONS;
- QUASARS