---
res:
  bibo_abstract:
  - Pulsar timing arrays (PTAs) are expected to detect gravitational waves (GWs) from
    individual low-redshift (z<1.5) compact supermassive (M>10^9 Msun) black hole
    (SMBH) binaries with orbital periods of approx. 0.1 - 10 yrs. Identifying the
    electromagnetic (EM) counterparts of these sources would provide confirmation
    of putative direct detections of GWs, present a rare opportunity to study the
    environments of compact SMBH binaries, and could enable the use of these sources
    as standard sirens for cosmology. Here we consider the feasibility of such an
    EM identification. We show that because the host galaxies of resolved PTA sources
    are expected to be exceptionally massive and rare, it should be possible to find
    unique hosts of resolved sources out to redshift z=0.2. At higher redshifts, the
    PTA error boxes are larger, and may contain as many as 100 massive-galaxy interlopers.
    The number of candidates, however, remains tractable for follow-up searches in
    upcoming wide-field EM surveys. We develop a toy model to characterize the dynamics
    and the thermal emission from a geometrically thin, gaseous disc accreting onto
    a PTA-source SMBH binary. Our model predicts that at optical and infrared frequencies,
    the source should appear similar to a typical luminous active galactic nucleus
    (AGN). However, owing to the evacuation of the accretion flow by the binary's
    tidal torques, the source might have an unusually low soft X-ray luminosity and
    weak UV and broad optical emission lines, as compared to an AGN powered by a single
    SMBH with the same total mass. For sources near z=1, the decrement in the rest-frame
    UV should be observable as an extremely red optical color. These properties would
    make the PTA sources stand out among optically luminous AGN, and could allow their
    unique identification.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Takamitsu
      foaf_name: Tanaka, Takamitsu
      foaf_surname: Tanaka
  - foaf_Person:
      foaf_givenName: Kristen
      foaf_name: Menou, Kristen
      foaf_surname: Menou
  - foaf_Person:
      foaf_givenName: Zoltán
      foaf_name: Haiman, Zoltán
      foaf_surname: Haiman
      foaf_workInfoHomepage: http://www.librecat.org/personId=7c006e8c-cc0d-11ee-8322-cb904ef76f36
  bibo_doi: 10.1111/j.1365-2966.2011.20083.x
  bibo_issue: '1'
  bibo_volume: 420
  dct_date: 2012^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/0035-8711
  dct_language: eng
  dct_publisher: Oxford University Press@
  dct_title: Electromagnetic counterparts of supermassive black hole binaries resolved
    by pulsar timing arrays@
...