Heidelberg 1999 – scientific programme
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GR: Gravitation und Relativitätstheorie
GR 11: Astrophysics
GR 11.2: Talk
Thursday, March 18, 1999, 14:40–15:00, AM1
Black Hole Formation in Dark Matter Halos — •Juan José Gracia Calvo and Max Camenzind — Landessternwarte Königstuhl
The cores of active galaxies are the most luminous objects in the universe. We do not only see them in our cosmic neighbourhood, they can be detected at high redshifts. Today we believe, that a supermassive black hole can be found in the very center of AGN. Matter accretion onto a black hole is believed to be the most effective energy production mechanism.
The problem how supermassive black holes are formed is not solved yet. Some early attemps have been done, but the proposed mechanism would only lead to the formation of these in very recent times. We study a new scenario, in which the black holes form in a CDM cosmology. While baryonic matter is smoothly distributed until after the recombination era, cold dark matter decouples very early from background expansion and DM inhomogeneities can grow long before recombination. After recombination baryonic matter finally decouples from photons and falls into the deep gravitational potential wells of the dark matter.
We numerically investigate the spherical accretion of baryonic matter into the potential well of dark matter. Though these are only preliminary results, and further investigation is necessary, our simulations suggest that massive cores with masses of 107 M⊙− 108 M⊙ might form as early as z=50−25. If these cores stay optically thick, they might cool, contract further, eventually become gravitationally unstable and collapse to a massive black hole.