1998/08/05 by Charles F. Gammie, Ramesh Narayan, R. D. Blandford +1 · 6 citations
Engineering · Physics and Astronomy · #Astrophysical Phenomena and Observations #Galaxies: Formation, Evolution, Phenomena #Heat Transfer Mechanisms #astro-ph
paper · pdf · doi:10.1086/307089
9 pages, 3 figures, latex, emulateapj.sty, submitted to ApJ
arxiv created 1998/08/05 · openalex publication_date 1999/05/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We estimate the accretion rate onto the black hole in the nucleus of NGC 4258. The result is model dependent. We find that a thin disk that is flat out to ≳2 × 10 3 GM / c 2 ( M ≡black hole mass) and that has inclination equal to that of the masing disk must have ≃ 0.01 M ☉ yr -1 for consistency with near-infrared data. A thin disk that is warped at ~10 3 GM / c 2 requires ≳ 1.5 × 10 -4 M ☉ yr -1 for consistency with near-infrared data. Reasonable warp models and the near-infrared data are not consistent with as low as the 7 × 10 -5 α M ☉ yr -1 proposed by Neufeld & Maloney. An advection-dominated flow model combined with the X-ray data implies ≃ 0.01 M ☉ yr -1 . Consistency with a tight 22 GHz upper limit on the flux from the central source requires a transition radius of ~(10-100) GM / c 2 , although the 22 GHz upper limit may be relaxed by appeal to free-free absorption. Physical conditions in the observed VLBI jet features can also be related to conditions in the inner accretion flow. We conclude with a list of observations that might further constrain .