Dark matter heating of gas accreting onto Sgr A*
| Autor: | Thomas W. Baumgarte, Elizabeth R Bennewitz, Stuart L. Shapiro, Cristian Gaidau |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Supermassive black hole Annihilation Bondi accretion 010308 nuclear & particles physics Astrophysics::High Energy Astrophysical Phenomena Galactic Center Dark matter FOS: Physical sciences Astronomy and Astrophysics General Relativity and Quantum Cosmology (gr-qc) Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics 01 natural sciences General Relativity and Quantum Cosmology Galaxy Accretion (astrophysics) Black hole Space and Planetary Science 0103 physical sciences Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 490:3414-3425 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | 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 onto Sgr A$^*$ in the Galactic center. Motivated by this observation we study the effects of such heating on Bondi accretion, i.e. spherically symmetric, steady-state Newtonian accretion onto 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 center of galaxies, and may help explain the low accretion rate observed for Sgr A$^*$. Comment: 13 pages, 9 figures, version accepted for publication in MNRAS |
| Databáze: | OpenAIRE |
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