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

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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.


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



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

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


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Monthly Notices of the Royal Astronomical Society: Letters


Oxford University Press (OUP), Royal Astronomical Society



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