Associating host galaxy candidates to massive black hole binaries resolved by pulsar timing arrays

Goldstein, J. M., Sesana, A., Holgado, A. M. and Veitch, J. (2019) Associating host galaxy candidates to massive black hole binaries resolved by pulsar timing arrays. Monthly Notices of the Royal Astronomical Society, 485(1), pp. 248-259. (doi: 10.1093/mnras/stz420)

Abstract

We propose a novel methodology to select host galaxy candidates of future pulsar timing array (PTA) detections of resolved gravitational waves (GWs) from massive black hole binaries (MBHBs). The method exploits the physical dependence of the GW amplitude on the MBHB chirp mass and distance to the observer, together with empirical MBH mass–host galaxy correlations, to rank potential host galaxies in the mass–redshift plane. This is coupled to a null-stream based likelihood evaluation of the GW amplitude and sky position in a Bayesian framework that assigns to each galaxy a probability of hosting the MBHB generating the GW signal. We test our algorithm on a set of realistic simulations coupling the likely properties of the first PTA resolved GW signal to synthetic all-sky galaxy maps. For a foreseeable PTA sky-localization precision of 100 deg2, we find that the GW source is hosted with 50%(90%) probability within a restricted number of ≲ 50( ≲ 500) potential hosts. These figures are orders of magnitude smaller than the total number of galaxies within the PTA sky error-box, enabling extensive electromagnetic follow-up campaigns on a limited number of targets.

• Item Type: Articles
• Additional Information: A.S. is supported by the Royal Society. J. V. is supported by STFC grant ST/K005014/1. A.M.H. is supported by the DOE NNSA Steward Science Graduate Fellowship under grant number DE-NA0003864.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Veitch, Dr John
• Authors: Goldstein, J. M., Sesana, A., Holgado, A. M., and Veitch, J.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Research Centre: College of Science and Engineering > School of Physics and Astronomy > Institute for Gravitational Research
• Journal Name: Monthly Notices of the Royal Astronomical Society
• Publisher: Oxford University Press
• ISSN: 0035-8711
• ISSN (Online): 1365-2966
• Published Online: 11 February 2019
• Copyright Holders: Copyright © 2019 The Authors
• First Published: First published in Monthly Notices of the Royal Astronomical Society 485:248-259
• Publisher Policy: Reproduced in accordance with the publisher copyright policy