Physical Sciences and Mathematics Commons^™

Neutron Stars And Black Holes As Machos, Aparna Venkatesan, Angela V. Olinto, James W. Truran

Physics and Astronomy

We consider the contribution of neutron stars and black holes to the dynamical mass of galactic halos. In particular, we show that if these compact objects were produced by an early generation of stars with initial metallicity 10^-4 Z_☉, they can contribute at most 30%-40% of the Galactic halo mass without creating supersolar levels of enrichment. We show that the case for halo neutron stars and black holes cannot be rejected on metal overproduction arguments alone because of the critical factor of the choice of progenitor metallicity in determining the yields. We show that this scenario satisfies …