Radiative efficiency of collisionless accretion

Andrei V. Gruzinov

    Research output: Contribution to journalArticle

    Abstract

    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
    Volume501
    Issue number2 PART 1
    DOIs
    StatePublished - Jul 10 1998

    Fingerprint

    accretion
    magnetic field
    magnetic fields
    field strength
    electron
    heat
    radii
    estimates
    electrons
    temperature

    Keywords

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

    ASJC Scopus subject areas

    • Space and Planetary Science

    Cite this

    Radiative efficiency of collisionless accretion. / Gruzinov, Andrei V.

    In: Astrophysical Journal, Vol. 501, No. 2 PART 1, 10.07.1998, p. 787-791.

    Research output: Contribution to journalArticle

    Gruzinov, Andrei V. / Radiative efficiency of collisionless accretion. In: Astrophysical Journal. 1998 ; Vol. 501, No. 2 PART 1. pp. 787-791.
    @article{a904166577594df5839e64bf13bde742,
    title = "Radiative efficiency of collisionless accretion",
    abstract = "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.",
    keywords = "Accretion, accretion disks, Black hole physics, MHD, Turbulence",
    author = "Gruzinov, {Andrei V.}",
    year = "1998",
    month = "7",
    day = "10",
    doi = "10.1086/305845",
    language = "English (US)",
    volume = "501",
    pages = "787--791",
    journal = "Astrophysical Journal",
    issn = "0004-637X",
    publisher = "IOP Publishing Ltd.",
    number = "2 PART 1",

    }

    TY - JOUR

    T1 - Radiative efficiency of collisionless accretion

    AU - Gruzinov, Andrei V.

    PY - 1998/7/10

    Y1 - 1998/7/10

    N2 - 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.

    AB - 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.

    KW - Accretion, accretion disks

    KW - Black hole physics

    KW - MHD

    KW - Turbulence

    UR - http://www.scopus.com/inward/record.url?scp=0032503777&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=0032503777&partnerID=8YFLogxK

    U2 - 10.1086/305845

    DO - 10.1086/305845

    M3 - Article

    VL - 501

    SP - 787

    EP - 791

    JO - Astrophysical Journal

    JF - Astrophysical Journal

    SN - 0004-637X

    IS - 2 PART 1

    ER -