Binary quasars

File Description SizeFormat 
Binary-quasars.pdfPublished version553.34 kBAdobe PDFView/Open
Title: Binary quasars
Authors: Mortlock, DJ
Webster, RL
Francis, PJ
Item Type: Journal Article
Abstract: Quasar pairs are either physically distinct binary quasars or the result of gravitational lensing. The majority of known pairs are in fact lenses, with a few confirmed as binaries, leaving a population of objects that have not yet been successfully classified. Building on the arguments of Kochanek, Falco & Muñoz, it is shown that there are no objective reasons to reject the binary interpretation for most of these. In particular, the similarity of the spectra of the quasar pairs appears to be an artefact of the generic nature of quasar spectra. The two ambiguous pairs discovered as part of the Large Bright Quasar Survey (Q 1429-053 and Q 2153-0256) are analysed using principal components analysis, which shows that their spectral similarities are not greater than expected for a randomly chosen pair of quasars from the survey. The assumption of the binary hypothesis allows the dynamics, time-scales and separation distribution of binary quasars to be investigated and constrained. The most plausible model is that the activity of the quasar is triggered by tidal interactions in a galatic merger, but that the (re-)activation of the galactic nuclei occurs quite late in the interaction, when the nuclei are within 80±30 kpc of each other. A simple dynamical friction model for the decaying orbits reproduces the observed distribution of projected separations, but the decay time inferred is comparable to a Hubble time. Hence it is predicted that binary quasars are only observable as such in the early stages of galactic collisions, after which the quiescent supermassive black holes orbit in the merger remnant for some time.
Issue Date: 11-Nov-1999
Date of Acceptance: 15-Jun-1999
URI: http://hdl.handle.net/10044/1/73481
DOI: https://doi.org/10.1046/j.1365-8711.1999.02872.x
ISSN: 0035-8711
Publisher: Oxford University Press (OUP)
Start Page: 836
End Page: 846
Journal / Book Title: Monthly Notices of the Royal Astronomical Society
Volume: 309
Issue: 4
Copyright Statement: © 1999 Oxford University Press. This is a pre-copy-editing, author-produced version of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version Daniel J. Mortlock, Rachel L. Webster, Paul J. Francis, Binary quasars, Monthly Notices of the Royal Astronomical Society, Volume 309, Issue 4, November 1999, Pages 836–846, https://doi.org/10.1046/j.1365-8711.1999.02872.x is available online at: https://doi.org/10.1046/j.1365-8711.1999.02872.x.
Keywords: Science & Technology
Physical Sciences
Astronomy & Astrophysics
galaxies : interactions
galaxies : nuclei
quasars : general
gravitational lensing
GRAVITATIONAL LENS CANDIDATE
NEARBY LUMINOUS QUASARS
SPACE-TELESCOPE IMAGES
ACTIVE GALACTIC NUCLEI
BLACK-HOLE BINARIES
DISK GALAXIES
DOUBLE QSO
SEPARATION
DISCOVERY
REDSHIFT
Science & Technology
Physical Sciences
Astronomy & Astrophysics
galaxies : interactions
galaxies : nuclei
quasars : general
gravitational lensing
GRAVITATIONAL LENS CANDIDATE
NEARBY LUMINOUS QUASARS
SPACE-TELESCOPE IMAGES
ACTIVE GALACTIC NUCLEI
BLACK-HOLE BINARIES
DISK GALAXIES
DOUBLE QSO
SEPARATION
DISCOVERY
REDSHIFT
astro-ph
astro-ph
Astronomy & Astrophysics
0201 Astronomical and Space Sciences
Publication Status: Published
Online Publication Date: 1999-11-11
Appears in Collections:Physics
Astrophysics



Unless otherwise indicated, items in Spiral are protected by copyright and are licensed under a Creative Commons Attribution NonCommercial NoDerivatives License.

Creative Commons