Radiative efficiency of collisionless accretion

Andrei V. Gruzinov

    Research output: Contribution to journalArticlepeer-review


    The radiative efficiency, η ≡ L/Ṁc2, of a slowly accreting black hole is estimated using a two-temperature model of accretion. The radiative efficiency depends on the magnetic field strength near the Schwarzschild radius. For weak magnetic fields, i.e., β-1 ≡ B2/8πp ≲ 10-3, the low efficiency η ∼ 10-4 that is assumed in some theoretical models is achieved. For β-1 > 10-3, a significant fraction of viscous heat is dissipated by electrons and radiated away resulting in η > 10-4. At equipartition magnetic fields, β-1 ∼ 1, we estimate η ∼ 10-1.

    Original languageEnglish (US)
    Pages (from-to)787-791
    Number of pages5
    JournalAstrophysical Journal
    Issue number2 PART 1
    StatePublished - Jul 10 1998


    • Accretion, accretion disks
    • Black hole physics
    • MHD
    • Turbulence

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science


    Dive into the research topics of 'Radiative efficiency of collisionless accretion'. Together they form a unique fingerprint.

    Cite this