A high signal-to-noise ratio composite quasar spectrum

Abstract

view Abstract Citations (608) References (11) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A High Signal-to-Noise Ratio Composite Quasar Spectrum Francis, Paul J. ; Hewett, Paul C. ; Foltz, Craig B. ; Chaffee, Frederic H. ; Weymann, Ray J. ; Morris, Simon L. 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 full text sources ADS |