Structure Formation and Exotic Compact Objects in a Dissipative Dark
  Sector
  We present the complete history of structure formation in a simple
dissipative dark-sector model. The model has only two particles: a dark
electron, which is a subdominant component of dark matter, and a dark photon.
Dark-electron perturbations grow from primordial overdensities, become
non-linear, and form dense dark galaxies. Bremsstrahlung cooling leads to
fragmentation of the dark-electron halos into clumps that vary in size from a
few to millions of solar masses, depending on the particle model parameters. In
particular, we show that asymmetric dark stars and black holes form within the
Milky Way from the collapse of dark electrons. These exotic compact objects may
be detected and their properties measured at new high-precision astronomical
observatories, giving insight into the particle nature of the dark sector
without the requirement of non-gravitational interactions with the visible
sector.
