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arXiv · 1904.03203

Radiation pattern and outflow geometry: a new probe of black hole spin?

W. Ishibashi·A. C. Fabian·C. S. Reynolds
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Abstract

We explore the impact of the central black hole (BH) spin on the large-scale properties of the host galaxy, by considering radiative feedback. The BH spin determines the radiation pattern from the accretion disc, which directly imprints on the geometry of the radiation-driven outflows. We show that for low BH spins, the emission is vertically focused, giving rise to polar/prolate outflows; while for high BH spins, the radiation pattern is more isotropic, leading to quasi-spherical/oblate outflows. Reversing the argument, we can potentially deduce the spin of the central BH from the observed morphology of galactic outflows. In principle, this may provide a novel way of constraining the central BH spin from galaxy-scale observations. Indeed, the BH spin can have significant macroscopic effects on galactic scales, ultimately shaping the large-scale feedback and the resulting obscuration.

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W. Ishibashi, A. C. Fabian, C. S. Reynolds. 2019-04-05. Radiation pattern and outflow geometry: a new probe of black hole spin?. https://doi.org/10.1093/mnras%2Fstz987

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