Stellar Disruption of Axion Miniclusters in the Milky Way
  Axion miniclusters are dense bound structures of dark matter axions that are
predicted to form in the post-inflationary Peccei-Quinn symmetry breaking
scenario. Although dense, miniclusters can easily be perturbed or even become
unbound by interactions with baryonic objects such as stars. Here, we
characterize the spatial distribution and properties of miniclusters in the
Milky Way (MW) today after undergoing these stellar interactions throughout
their lifetime. We do this by performing a suite of Monte Carlo simulations
which track the miniclusters' structure and, in particular, accounts for
partial disruption and mass loss through successive interactions. We consider
two density profiles - Navarro-Frenk-White (NFW) and Power-law (PL) - for the
individual miniclusters in order to bracket the uncertainties on the
minicluster population today due to their uncertain formation history. For our
fiducial analysis at the Solar position, we find a survival probability of 99%
for miniclusters with PL profiles and 46% for those with NFW profiles. Our work
extends previous estimates of this local survival probability to the entire MW.
We find that towards the Galactic center, the survival probabilities drop
drastically. Although we present results for a particular initial halo mass
function, our simulations can be easily recast to different models using the
provided data and code. Finally, we comment on the impact of our results on
lensing, direct, and indirect detection.
