2002/12/17 by I. Hook, I. M. Hook, P. A. Shaver +4 · 1 citation
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1051/0004-6361:20021803
published as Astron.Astrophys. 399 (2003) 469-488 · 20 pages, 8 figures. Accepted for publication in Astronomy and Astrophysics
arxiv created 2002/12/17 · openalex publication_date 2003/02/01 · arxiv updated 2009/12/01 · openalex created_date 2022/10/04 · openalex updated_date 2026/07/31
We present optical spectra and redshift measurements for 178 flat-spectrum objects from the Parkes quarter-Jansky flat-spectrum sample. These spectra were obtained in order to compile a complete sample of quasars for use in a study of quasar evolution. We present a composite optical spectrum made from the subset of 109 quasars that have flux densities in the range , and make a comparison with a composite for radio-quiet QSOs from the Large Bright Quasar Survey. Our large sample of radio-loud quasars allows us to strengthen previous reports that the Lyα and CIV emission lines have larger equivalent width in radio-loud quasars than radio-quiet QSOs to greater than the 3σ level. However we see no significant difference in the equivalent widths of CIII] or MgII. We also show that the flux decrements across the Lyman-α line (DA) measured from these spectra show the same trend with redshift as for optically selected QSOs.