LBQS 0015+0239: A binary quasar with small angular separation

Christopher D Impey, Cathy E. Petry, Craig B. Foltz, Paul C. Hewett, Frederic H. Chaffee

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We present spectroscopic observations with the Keck Low-Resolution Imaging Spectrometer of LBQS 0015+0239, a pair of quasars at z = 2.45 with a separation of Δθ = ″2.2 (projected linear distance of 17.8 h 70-1 kpc, for Ωm = 0.3, A = 0.7). Lensing is an unlikely interpretation for the images since the spectra show significant differences in the N V and C IV emission-line profiles and there is no luminous galaxy at the anticipated lens position. Rather, we interpret this pair as the highest redshift known example of a binary quasar. The redshift difference of 661 ± 173 km s-1 between the two components is inconsistent with the lensing expectation but is consistent with the line-of-sight velocity difference of a bound pair of galaxies. The spectra show associated narrow metal absorption in highly ionized species of C and N, with a systemic velocity difference of 492 ± 6 km s-1. It is likely that this absorption arises in a group or cluster of galaxies surrounding the quasar pair. After a thorough search, the Large Bright Quasar Survey is known to contain one gravitational lens and four probable binary pairs. The existence of close binaries is evidence that quasar activity can be triggered by galaxy interactions. We speculate that the close pair LBQS 0015+0239 is a rare example of the premerger state of two supermassive black holes.

Original languageEnglish (US)
Pages (from-to)623-633
Number of pages11
JournalAstrophysical Journal
Volume574
Issue number2 I
DOIs
StatePublished - Aug 1 2002

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quasars
galaxies
spectrometer
metal
interacting galaxies
gravitational lenses
imaging spectrometers
line of sight
lenses
profiles
metals

Keywords

  • Galaxies: interactions
  • Quasars: absorption lines
  • Quasars: emission lines

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Impey, C. D., Petry, C. E., Foltz, C. B., Hewett, P. C., & Chaffee, F. H. (2002). LBQS 0015+0239: A binary quasar with small angular separation. Astrophysical Journal, 574(2 I), 623-633. https://doi.org/10.1086/341064

LBQS 0015+0239 : A binary quasar with small angular separation. / Impey, Christopher D; Petry, Cathy E.; Foltz, Craig B.; Hewett, Paul C.; Chaffee, Frederic H.

In: Astrophysical Journal, Vol. 574, No. 2 I, 01.08.2002, p. 623-633.

Research output: Contribution to journalArticle

Impey, CD, Petry, CE, Foltz, CB, Hewett, PC & Chaffee, FH 2002, 'LBQS 0015+0239: A binary quasar with small angular separation', Astrophysical Journal, vol. 574, no. 2 I, pp. 623-633. https://doi.org/10.1086/341064
Impey, Christopher D ; Petry, Cathy E. ; Foltz, Craig B. ; Hewett, Paul C. ; Chaffee, Frederic H. / LBQS 0015+0239 : A binary quasar with small angular separation. In: Astrophysical Journal. 2002 ; Vol. 574, No. 2 I. pp. 623-633.
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