TY - JOUR
T1 - Dark matter heating of gas accreting onto sgr A
AU - Bennewitz, Elizabeth R.
AU - Gaidau, Cristian
AU - Baumgarte, Thomas W.
AU - Shapiro, Stuart L.
N1 - Funding Information:
We thank C. Gammie, B. Fields, and J. Shelton for helpful discussions. ERB acknowledges support through an undergraduate research fellowship at Bowdoin College. This work was supported in part by NSF grant PHYS-1707526 to Bowdoin College, NSF grant PHY-1662211 and NASA grant 80NSSC17K0070 to the University of Illinois at Urbana-Champaign, as well as through sabbatical support from the Simons Foundation (Grant No. 561147 to TWB).
Publisher Copyright:
© 2019 The Author(s)
PY - 2019/12/1
Y1 - 2019/12/1
N2 - We study effects of heating by dark matter (DM) annihilation on black hole gas accretion. We observe that, for reasonable assumptions about DM densities in spikes around supermassive black holes, as well as DM masses and annihilation cross-sections within the standard WIMP model, heating by DM annihilation may have an appreciable effect on the accretion on to Sgr A∗ in the Galactic Centre. Motivated by this observation we study the effects of such heating on Bondi accretion, i.e. spherically symmetric, steady-state Newtonian accretion on to a black hole. We consider different adiabatic indices for the gas, and different power-law exponents for the DM density profile. We find that typical transonic solutions with heating have a significantly reduced accretion rate. However, for many plausible parameters, transonic solutions do not exist, suggesting a breakdown of the underlying assumptions of steady-state Bondi accretion. Our findings indicate that heating by DM annihilation may play an important role in the accretion onto supermassive black holes at the centre of galaxies, and may help explain the low accretion rate observed for Sgr A∗
AB - We study effects of heating by dark matter (DM) annihilation on black hole gas accretion. We observe that, for reasonable assumptions about DM densities in spikes around supermassive black holes, as well as DM masses and annihilation cross-sections within the standard WIMP model, heating by DM annihilation may have an appreciable effect on the accretion on to Sgr A∗ in the Galactic Centre. Motivated by this observation we study the effects of such heating on Bondi accretion, i.e. spherically symmetric, steady-state Newtonian accretion on to a black hole. We consider different adiabatic indices for the gas, and different power-law exponents for the DM density profile. We find that typical transonic solutions with heating have a significantly reduced accretion rate. However, for many plausible parameters, transonic solutions do not exist, suggesting a breakdown of the underlying assumptions of steady-state Bondi accretion. Our findings indicate that heating by DM annihilation may play an important role in the accretion onto supermassive black holes at the centre of galaxies, and may help explain the low accretion rate observed for Sgr A∗
KW - Accretion
KW - Accretion discs
KW - Black hole physics
KW - Dark matter
KW - Galaxy: Centre
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U2 - 10.1093/mnras/stz2781
DO - 10.1093/mnras/stz2781
M3 - Article
AN - SCOPUS:85079624892
VL - 490
SP - 3414
EP - 3425
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 3
ER -