1995/02/14 by I. Hook, I. M. Hook, R. G. McMahon +5 · 41 citations
Physics and Astronomy · #Astronomy #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Luminosity function #OVV quasar #Physics #Quasar #Redshift #astro-ph
paper · pdf · doi:10.1093/mnras/273.1.l63
published in Monthly Notices of the Royal Astronomical Society 273(1), L63-L67 (Oxford University Press) · 5 pages, one uuencoded compressed postscipt file (created with uufiles) including figures. MNRAS Letter, in press.
arxiv created 1995/02/14 · openalex publication_date 1995/03/01 · arxiv updated 2016/06/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report the discovery of a radio-loud quasar with a redshift of 4.30. This object, which is the first radio-selected quasar with a redshift greater than 4, was discovered during an observational investigation into the evolution of the luminosity function of radio-loud quasars. Here we describe results based on a sample of ∼ 300 flat-spectrum radio sources with |S5GHz\gt200| mJy. In this study, rather than carry out an indiscriminate redshift campaign on all the radio sources, we have used the APM POSS catalogue to pre-select a subset of stellar-like optical counterparts with red optical colours. Such a subsample is expected to contain a high fraction of high-redshift quasars. 10 of the ∼ 300 sources were selected for follow-up optical spectroscopy, and three of these are identified as quasars with redshifts greater than 3.0. One of the radio sources, GB1508+5714, is a quasar with z = 4.30 and m(R)~19.