1999/07/18 by Tal Alexander · 4 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Black hole (networking) #Cusp (singularity) #Extinction (optical mineralogy) #Galactic Center #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Physics #Pulsars and Gravitational Waves Research #Star cluster #Stars #Stellar dynamics #Supermassive black hole #astro-ph
paper · pdf · doi:10.1086/308129
ApJ accepted. 35 pages, 9 figures
arxiv created 1999/07/18 · openalex publication_date 1999/12/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We analyze three sets of infrared star counts in the inner ~0.5 pc of the Galactic center. We perform statistical tests on the star counts and model in detail the extinction field and the effects of dwarf-giant collisions on the luminosity function. We find that both the star counts and the depletion of the brightest stars in the inner ~0.05 pc can be explained by an n ∝ r -α stellar cusp with α in the range 3/2-7/4, in which the envelopes of the brightest giants are destroyed by stellar collisions. Such a cusp is consistent with the Bahcall-Wolf solution for the distribution of stars that have undergone two-body relaxation around a black hole. We show that systematic uncertainties due to variable extinction and unrelaxed stars are probably small, but deeper star counts are required to confirm these results. We estimate that the tidal disruption rate of cusp stars by the black hole is a few × 10 -5 yr -1 .