Science with the space-based interferometer LISA. V: Extreme mass-ratio inspirals

Research output: Contribution to journalArticlepeer-review

Authors

  • Stanislav Babak
  • Jonathan R. Gair
  • Enrico Barausse
  • C. F. Sopuerta
  • Pau Amaro-seoane
  • Emanuele Berti
  • Antoine Petiteau
  • Antoine Klein

Colleges, School and Institutes

Abstract

The space-based Laser Interferometer Space Antenna (LISA) will be able to observe the gravitational-wave signals from systems comprised of a massive black hole and a stellar-mass compact object. These systems are known as extreme-mass-ratio inspirals (EMRIs) and are expected to complete $\sim 10^4-10^5$ cycles in band, thus allowing exquisite measurements of their parameters. In this work, we attempt to quantify the astrophysical uncertainties affecting the predictions for the number of EMRIs detectable by LISA, and find that competing astrophysical assumptions produce a variance of about three orders of magnitude in the expected intrinsic EMRI rate. However, we find that irrespective of the astrophysical model, at least a few EMRIs per year should be detectable by the LISA mission, with up to a few thousands per year under the most optimistic astrophysical assumptions. We also investigate the precision with which LISA will be able to extract the parameters of these sources. We find that typical fractional statistical errors with which the intrinsic parameters (redshifted masses, massive black hole spin and orbital eccentricity) can be recovered are $\sim 10^{-6}$--$10^{-4}$. Luminosity distance (which is required to infer true masses) is inferred to about $10\%$ precision and sky position is localized to a few square degrees, while tests of the multipolar structure of the Kerr metric can be performed to percent-level precision or better.

Bibliographic note

revtex4-1, 13 figures, 22 pages

Details

Original languageEnglish
Article number103012
JournalPhysical Review D
Volume95
Publication statusPublished - 31 May 2017

Keywords

  • gr-qc, astro-ph.CO, astro-ph.GA