Broad absorption line quasars in the early data release from the Sloan Digital Sky Survey

Alin Tolea, Julian H. Krolik, Zlatan Tsvetanov

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48 Citations (Scopus)


A new broad absorption line (BAL) quasar sample is derived from the first data released by the Sloan Digital Sky Survey. With 116 objects, it is the largest BAL quasar sample yet assembled. Over the redshift range 1.8 ≤, z ≤, 3.8, the crude fraction with broad absorption in the C IV line is ≃ 15%. This fraction may be subject to small selection-efficiency adjustments. There are also hints of redshift dependence in the BAL quasar fraction. The sample is large enough to permit the first estimate of the distribution of the "balnicity index": subject to certain arbitrary parameters in the definition of this quantity, it is very broad, with (roughly) equal numbers of objects per logarithmic interval of balnicity. BAL quasars are also found to be redder on average than non-BAL quasars. The fraction of radio-loud BAL quasars is (weakly) consistent with the fraction of radio-loud ordinary quasars.

Original languageEnglish
Pages (from-to)L31-L35
JournalAstrophysical Journal
Issue number1 II
Publication statusPublished - 10 Oct 2002



  • Galaxies: active
  • Quasars: absorption lines

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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