1999/06/30 by Taro Nakano, Junichiro Makino · 1 citation
Engineering · Physics and Astronomy · #Astronomy and Astrophysical Research #Black hole (networking) #Cusp (singularity) #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Lenticular galaxy #Peculiar galaxy #Radio galaxy #Space Technology and Applications #astro-ph
paper · pdf · doi:10.1086/312338
7 pages, 6 figures, LaTeX, new results added, accepted for publication in ApJ Letters
arxiv created 1999/09/08 · openalex publication_date 1999/11/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In this Letter, we show that a massive black hole (MBH) that falls into the center of a galaxy on the dynamical timescale leaves a weak cusp (rho~r-1&solm0;2) around it, which is in good agreement with the recent observations of luminous elliptical galaxies by the Hubble Space Telescope. Such an event is a natural outcome of the merging of two galaxies that have central MBHs. This is the only known mechanism for forming weak cusps in luminous elliptical galaxies. Therefore, the existence of the weak cusps indicates that the central black holes of luminous elliptical galaxies have fallen to the center from outside, most likely during a major merger event.