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Sgr A* envelope explosion and the young stars in the centre of the Milky Way

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journal contribution
posted on 10.08.2018, 14:50 by Sergei Nayakshin, Kastytis Zubovas
Sgr A* is the supermassive black hole residing in the centre of the Milky Way. There is plenty of observational evidence that a massive gas cloud fell into the central parsec of the Milky Way ∼6 Myr ago, triggering formation of a disc of young stars and activating Sgr A*. In addition to the disc, there is an unexplained population of young stars on randomly oriented orbits. Here we hypothesize that these young stars were formed by fragmentation of a massive quasi-spherical gas shell driven out from Sgr A* potential well by an energetic outflow. To account for the properties of the observed stars, the shell must be more massive than 105 solar masses, be launched from inside ∼0.01 pc, and the feedback outflow has to be highly super-Eddington albeit for a brief period of time, producing kinetic energy of at least 1055 erg. The young stars in the central parsec of the Galaxy may be a unique example of stars formed from atomic rather than molecular hydrogen, and forged by extreme pressure of black hole outflows.

Funding

KZ is funded by the Research Council Lithuania through the grant no. MIP-17-78. SN acknowledges support by STFC grant ST/K001000/1.

History

Citation

Monthly Notices of the Royal Astronomical Society: Letters, 2018, 478(1) pp. L127–L131.

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Version

VoR (Version of Record)

Published in

Monthly Notices of the Royal Astronomical Society: Letters

Publisher

Oxford University Press (OUP), Royal Astronomical Society

eissn

1745-3933

Acceptance date

23/04/2018

Copyright date

2018

Available date

10/08/2018

Publisher version

https://academic.oup.com/mnrasl/article/478/1/L127/4996354

Language

en