SUPERMASSIVE BLACK HOLE FORMATION AT HIGH REDSHIFTS THROUGH A PRIMORDIAL MAGNETIC FIELD
- Raman Research Institute, C. V. Raman Avenue, Sadashivanagar, Bengalooru, 560 080 (India)
- Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States)
It has been proposed that primordial gas in early dark matter halos, with virial temperatures T{sub vir} {approx}> 10{sup 4} K, can avoid fragmentation and undergo rapid collapse, possibly resulting in a supermassive black hole. This requires the gas to avoid cooling and to remain at temperatures near T {approx} 10{sup 4} K. We show that this condition can be satisfied in the presence of a sufficiently strong primordial magnetic field, which heats the collapsing gas via ambipolar diffusion. If the field has a strength above |B | {approx}>3.6 (comoving) nG, the collapsing gas is kept warm (T {approx} 10{sup 4} K) until it reaches the critical density n{sub crit} {approx} 10{sup 3} cm{sup -3} at which the rotovibrational states of H{sub 2} approach local thermodynamic equilibrium. H{sub 2} cooling then remains inefficient and the gas temperature stays near {approx}10{sup 4} K, even as it continues to collapse at higher densities. The critical magnetic field strength required to permanently suppress H{sub 2} cooling is somewhat higher than the upper limit of {approx}2 nG from the cosmic microwave background. However, it can be realized in the rare {approx}>(2-3){sigma} regions of the spatially fluctuating B field; these regions contain a sufficient number of halos to account for z {approx} 6 quasar black holes.
- OSTI ID:
- 21464832
- Journal Information:
- Astrophysical Journal, Vol. 721, Issue 1; Other Information: DOI: 10.1088/0004-637X/721/1/615; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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