Binary black hole accretion during inspiral and merger

Brian D. Farris, Paul Duffell, Andrew I. MacFadyen, Zoltán Haiman

    Research output: Contribution to journalArticle

    Abstract

    We present the results of 2D, moving mesh, viscous hydrodynamical simulations of accretion on to merging supermassive black hole (SMBH) binaries. We include viscous heating, shock heating, and radiative cooling, and simulate the transition from the 'pre-decoupling' epoch, where the inspiral time-scale is longer than the viscous time-scale, to the 'post-decoupling' epoch, where the inspiral time-scale is shorter than the viscous time-scale.We find that there is no abrupt halt to the accretion at decoupling, but rather the accretion shows a slow decay, with significant accretion well after the expected decoupling. Moreover, we find that the luminosity in X-rays is significantly higher prior to the merger, as orbital energy from the SMBH binary is converted to heat via strong shocks inside the cavity, and radiated away. Following the merger, the cavity refills viscously and the accretion rate relaxes to the Shakura-Sunyaev value, while the X-ray luminosity drops as the shocks quickly dissipate.

    Original languageEnglish (US)
    Pages (from-to)L80-L84
    JournalMonthly Notices of the Royal Astronomical Society: Letters
    Volume447
    Issue number1
    DOIs
    StatePublished - Nov 26 2014

    Fingerprint

    merger
    decoupling
    accretion
    timescale
    cavity
    shock
    luminosity
    time measurement
    shock heating
    heating
    cavities
    mesh
    x rays
    cooling
    orbitals
    heat
    decay
    simulation
    energy

    Keywords

    • Accretion
    • Accretion discs - black hole physics - hydrodynamics

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Binary black hole accretion during inspiral and merger. / Farris, Brian D.; Duffell, Paul; MacFadyen, Andrew I.; Haiman, Zoltán.

    In: Monthly Notices of the Royal Astronomical Society: Letters, Vol. 447, No. 1, 26.11.2014, p. L80-L84.

    Research output: Contribution to journalArticle

    Farris, Brian D. ; Duffell, Paul ; MacFadyen, Andrew I. ; Haiman, Zoltán. / Binary black hole accretion during inspiral and merger. In: Monthly Notices of the Royal Astronomical Society: Letters. 2014 ; Vol. 447, No. 1. pp. L80-L84.
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