1999/06/16 by C. R. Shrader, Chris Shrader, Lev Titarchuk
Physics and Astronomy · #Accretion (finance) #Accretion disc #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Context (archaeology) #Galaxies: Formation, Evolution, Phenomena #Nova (rocket) #Observable #RADIUS #Spectral line #astro-ph
paper · pdf · doi:10.1086/312194
14 pages, 3 figures, The paper is accepted for publication in the Astrophysical Journal Letters
arxiv created 1999/06/16 · openalex publication_date 1999/08/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We offer a brief description of the bulk motion Comptonization (BMC) model for accretion onto black holes, illustrated by its application to observational data for LMC X-1 and Nova Muscae 1991. We then extract some physical parameters of these systems from observables within the context of the BMC model, drawing from results on GRO J1655-40, for which we presented extensive analysis previously. We derive estimates of the mass, (16 ± 1) M ☉ × [0.5/ cos( i )] 1/2 , and mass accretion rate in the disk in Eddington units ( d ≃ 2) for LMC X-1 and (24 ± 1) M ☉ × [0.5/ cos( i )] 1/2 d 5.5 and ( d ≃ 3) for Nova Muscae 1991, where cos( i ) and d 5.5 are the inclination angle cosine and distance in 5.5 kpc units, respectively. Differences between these estimates and previous estimates based on dynamical studies are discussed. It is further shown that the disk inner radius increases with the high-to-low-state transition in Nova Muscae 1991. Specifically, our analysis suggests that the inner disk radius increases to r in ≃ 17 Scwarzschild radii as the transition to the low-hard state occurs.