Forming supermassive black hole seeds under the influence of a nearby anisotropic multifrequency source.
The photodissociation of H2by a nearby anisotropic source of radiation is seen as a critical component in creating an environment in which a direct collapse black hole may form. Employing radiative transfer we model the effect of multifrequency (0.76-60 eV) radiation on a collapsing halo at high redshift. We vary both the shape of the spectrum which emits the radiation and the distance to the emitting galaxy. We use blackbody spectra with temperatures ofT= 104K and 105K and a realistic stellar spectrum. We find that an optimal zone exists between 1 and 4 kpc from the emitting galaxy. If the halo resides too close to the emitting galaxy the photoionizing radiation creates a large H ii region which effectively disrupts the collapsing halo, too far from the source and the radiation flux drops below the level of the expected background and the H2fraction remains too high. When the emitting galaxy is initially placed between 1 and 2 kpc from the collapsing halo, with a spectral shape consistent with a star-forming high-redshift galaxy, then a large central core forms. The mass of the central core is between 5000 and 10 000 M⊙at a temperature of approximately 1000 K. This core is however surrounded by a reservoir of hotter gas at approximately 8000 K, which leads to mass inflow rates of the order of ∼0.1 M⊙yr-1.
Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE, UK; Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki, Finland.
John A
JA
Regan
Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2a, FI-00014 Helsinki, Finland.
Peter H
PH
Johansson
Center for Relativistic Astrophysics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30332, USA.
John H
JH
Wise
cosmology: theory; methods: numerical