Title:	Cosmological magnetic braking and the formation of high-redshift, super-massive black holes
Authors:	Pandey, Kanhaiya L. Sethi, S.K. Ratra, Bharat
Keywords:	black hole physics magnetic fields galaxies magnetic fields quasars general
Issue Date:	Jun-2019
Publisher:	Oxford University Press on behalf of the Royal Astronomical Society
Citation:	Monthly Notices of the Royal Astronomical Society, 2019, Vol. 486, p 1629–1640
Abstract:	We study the effect of magnetic braking due to a primordial magnetic field in the context of the formation of massive (≳104M☉) direct-collapse black holes (DCBHs) at high redshifts. Under the assumption of axial symmetry, we analytically compute the effect of magnetic braking on the angular momentum of gas collapsing into the potential well of massive dark matter haloes (≃107-9M☉) which are spun up by gravitational tidal torques. We find that a primordial magnetic field of strength B0 ≃ 0.1 nG (comoving) can remove the initial angular momentum gained by the in-falling gas due to tidal torques, thus significantly lowering the angular momentum barrier to the formation of DCBHs. These magnetic field strengths are consistent with the bounds on primordial fields from astrophysical and cosmological measurements and they are large enough to seed observed galactic magnetic fields.
Description:	Open Access
URI:	http://hdl.handle.net/2289/7258
ISSN:	0035-8711 1365-2966 - (online)
Alternative Location:	https://ui.adsabs.harvard.edu/abs/2019MNRAS.486.1629P/abstract https://arxiv.org/abs/1901.01434 https://doi.org/10.1093/mnras/stz939
Copyright:	2019 The Author(s)
Appears in Collections:	Research Papers (A&A)

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