Radio properties of optically selected quasars

Eric J. Hooper, Christopher D Impey, Craig B. Foltz, Paul C. Hewett

Research output: Contribution to journalArticle

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Abstract

Approximately one-quarter (256 objects) of the Large Bright Quasar Survey (LBQS) has been observed with the VLA at 8.4 GHz, resulting in 44 detections (17%) with a median 3 σ noise limit of 0.29 mJy. Quasars with radio luminosity detectable at this limit are underrepresented at faint absolute blue magnitudes (MB ≥ -24), an effect which cannot be explained by a potential LBQS selection bias against quasars which have large radio luminosities and small optical luminosities. The radio-loud (8 GHz luminosity > 1025 W Hz-1) fraction is observed to change as a function of redshift and MB, for MB < -24, although the causal variable is ambiguous. The description most consistent with the available data is that radio-loud fraction is approximately constant over the range -27.5 ≲ MB ≲ -24 and increases at brighter absolute magnitudes. The radio-loud fraction as a function of redshift reaches a local maximum at z ≈ 1, and, aside from the effects of increased radio-loud fraction at bright MB, remains roughly constant to redshifts approaching 5. The log R8.4 distribution (radio-to-optical luminosity ratio) of the current LBQS sample may be bimodal, but the results of statistical tests are ambiguous, requiring a larger sample size to become definite.

Original languageEnglish (US)
Pages (from-to)62-79
Number of pages18
JournalAstrophysical Journal
Volume445
Issue number1
StatePublished - May 20 1995

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quasars
luminosity
radio
statistical tests

Keywords

  • Quasars: general
  • Radio continuum: galaxies
  • Surveys

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Hooper, E. J., Impey, C. D., Foltz, C. B., & Hewett, P. C. (1995). Radio properties of optically selected quasars. Astrophysical Journal, 445(1), 62-79.

Radio properties of optically selected quasars. / Hooper, Eric J.; Impey, Christopher D; Foltz, Craig B.; Hewett, Paul C.

In: Astrophysical Journal, Vol. 445, No. 1, 20.05.1995, p. 62-79.

Research output: Contribution to journalArticle

Hooper, EJ, Impey, CD, Foltz, CB & Hewett, PC 1995, 'Radio properties of optically selected quasars', Astrophysical Journal, vol. 445, no. 1, pp. 62-79.
Hooper EJ, Impey CD, Foltz CB, Hewett PC. Radio properties of optically selected quasars. Astrophysical Journal. 1995 May 20;445(1):62-79.
Hooper, Eric J. ; Impey, Christopher D ; Foltz, Craig B. ; Hewett, Paul C. / Radio properties of optically selected quasars. In: Astrophysical Journal. 1995 ; Vol. 445, No. 1. pp. 62-79.
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