Evolution of dwarf galaxies hosting GW150914-like events [GA]

http://arxiv.org/abs/1901.04494


Here we present a detailed analysis of the properties and evolution of different dwarf galaxies, candidate to host the coalescence of black hole binary systems (BHB) generating GW150914-like events. By adopting a novel theoretical framework coupling the binary population synthesis code \texttt{SeBa} with the Galaxy formation model \texttt{GAMESH}, we can investigate the detailed evolution of these objects in a well resolved cosmological volume of 4~cMpc, having a Milky Way-like (MW) galaxy forming at its center. We identify three classes of interesting candidate galaxies: MW progenitors, dwarf satellites and dwarf galaxies evolving in isolation. We find that: (i) despite differences in individual histories and specific environments the candidates reduce to only nine representative galaxies; (ii) among them, $\sim44\%$ merges into the MW halo progenitors by the redshift of the expected signal, while the remaining dwarfs are found as isolated or as satellites of the MW and their evolution is strongly shaped by both peculiar dynamical history and environmental feedback; (iii) a stringent condition for the environments where GW150914-like binaries can form comes from a combination of the accretion history of their DM halos and the radiative feedback in the high redshift universe; (iv) by comparing with the observed catalogues from DGS and ALLSMOG surveys we find two observed dwarfs respecting the properties predicted by our model. We finally note how the present analysis opens the possibility to build future strategies for host galaxy identification.

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S. Marassi, L. Graziani, M. Ginolfi, et. al.
Wed, 16 Jan 19
7/76

Comments: MNRAS in press