Radiation pattern and outflow geometry: a new probe of black hole spin?. (arXiv:1904.03203v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Ishibashi_W/0/1/0/all/0/1">W. Ishibashi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fabian_A/0/1/0/all/0/1">A. C. Fabian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reynolds_C/0/1/0/all/0/1">C. S. Reynolds</a>

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.

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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