Athena Stacy, Andreas H. Pawlik, Volker Bromm, Abraham Loeb
We numerically study the mutual interaction between dark matter (DM) and
Population III (Pop III) stellar systems in order to explore the possibility of
Pop III dark stars within this physical scenario. We perform a cosmological
simulation, initialized at z ~ 100, which follows the evolution of gas and DM.
We analyze the formation of the first minihalo at z ~ 20 and the subsequent
collapse of the gas to densities of 10^12 cm^-3. We then use this simulation to
initialize a set of smaller-scale `cut-out' simulations in which we further
refine the DM to have spatial resolution similar to that of the gas. We test
multiple DM density profiles, and we employ the sink particle method to
represent the accreting star-forming region. We find that, for a range of DM
configurations, the motion of the Pop III star-disk system serves to separate
the positions of the protostars with respect to the DM density peak, such that
there is insufficient DM to influence the formation and evolution of the
protostars for more than ~ 5000 years. In addition, the star-disk system causes
gravitational scattering of the central DM to lower densities, further
decreasing the influence of DM over time. Any DM-powered phase of Pop III stars
will thus be very short-lived for the typical multiple system, and DM will not
serve to significantly prolong the life of Pop III stars.
View original:
http://arxiv.org/abs/1111.1527
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