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

Alin Tolea, Julian H. Krolik, Zlatan Tsvetanov

Research output: Contribution to journalReview article

46 Citations (Scopus)

Abstract

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
JournalAstrophysical Journal
Volume578
Issue number1 II
DOIs
Publication statusPublished - 10 Oct 2002
Externally publishedYes

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quasars
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Keywords

  • Galaxies: active
  • Quasars: absorption lines

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Space and Planetary Science

Cite this

Broad absorption line quasars in the early data release from the Sloan Digital Sky Survey. / Tolea, Alin; Krolik, Julian H.; Tsvetanov, Zlatan.

In: Astrophysical Journal, Vol. 578, No. 1 II, 10.10.2002.

Research output: Contribution to journalReview article

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abstract = "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.",
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N2 - 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.

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