2003/10/28 by Stirling A. Colgate, Renyue Cen, Hui Li +2
Physics and Astronomy · #Angular momentum #Astrophysical Phenomena and Observations #Black hole (networking) #Galaxies: Formation, Evolution, Phenomena #Instability #Pulsars and Gravitational Waves Research #Rossby wave #Supermassive black hole #Supernova #Turbulence #Vortex #astro-ph
paper · pdf · doi:10.1086/380426
published as Astrophys.J. 598 (2003) L7-L10 · 10 pages, to be published in ApJ Letters Nov. 2003
arxiv created 2003/10/28 · openalex publication_date 2003/10/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
A scenario is put forth for the formation of supermassive black holes at the centers of galaxies. It depends uon the formation of a Mestel disk with a flat rotation curve, M < r ∝ r and Σ ∝ 1/ r . Such disks could form from the collapse of uniformly rotating, isolated, gaseous clouds, either protogalactic, galaxy-mass damped Lyα clouds or the gas that survives galaxy mergers. We propose that in either case the disk will be unstable to the Rossby vortex instability (RVI). This instability grows from any large, steep pressure gradient in an optically thick disk. Such pressure gradients either occur adjacent to compact objects or could be triggered by heating from individual supernovae in and around the disk. Upon excitation, the RVI transports angular momentum outward, accreting nearly all mass within the initiation radius. We have calculated that in very thin disks, the nonlinear vortices initiated by the RVI can transport angular momentum far more efficiently than turbulence. Compared to a viscosity-based Shakura-Sunyaev disk, the RVI transports angular momentum out to a much larger radius, so more mass is accreted into the central black hole. A typical galaxy rotational velocity is v rot = 200 km s -1 , and the critical column density, necessary to initiate the RVI, is Σ CCD ≃ 100 g cm -2 . For M < r = 2π r 2 Σ, we have r CCD = v /(2πΣ CCD G ), and the mass accreted becomes M BH = v /(2πΣ CCD G 2 ) = 3 × 10 7 M ☉ . Both the black hole mass M BH and its v dependence are in good agreement with recent observations, because v rot = σ c , where σ c is the velocity dispersion of the bulge at the radius of mutual contact.