http://arxiv.org/abs/1709.03119
The Milky Way centre exhibits an intense flux in the gamma and X-ray bands, whose origin is partly ascribed to the possible presence of a large population of millisecond pulsars and cataclysmic variables, respectively. However, the number of sources required to give rise to such excess is much larger than what is expected from our current understanding of star formation and evolution, opening a series of questions about the formation history of the Galactic nucleus. In this paper we make use of direct N-body simulations to investigate whether these sources could have been brought to the Galactic centre by a population of star clusters that underwent orbital decay and formed the Galactic nuclear cluster. Our results suggest that the gamma ray emission is compatible with a population of MSPs that were mass segregated in their parent clusters, while the X-ray component likely owes, at least in part, to a consistent population of CVs born via dynamical interactions in dense star clusters. We discuss how high-energy emission can be used to detect massive black holes in dwarf galaxies.
M. Arca-Sedda, B. Kocsis and T. Brandt
Tue, 12 Sep 17
15/71
Comments: 13 pages, 12 figures and 5 tables. To appear in MNRAS