Stellar Feedback in Dwarf Galaxy Formation
Sergey Mashchenko,*
James Wadsley,
H. M. P. Couchman
Dwarf galaxies pose substantial challenges for cosmological
models. In particular, current models predict a dark-matter
density that is divergent at the center, which is in sharp contrast
with observations that indicate a core of roughly constant density.
Energy feedback, from supernova explosions and stellar winds,
has been proposed as a major factor shaping the evolution of
dwarf galaxies. We present detailed cosmological simulations
with sufficient resolution both to model the relevant physical
processes and to directly assess the impact of stellar feedback
on observable properties of dwarf galaxies. We show that feedback
drives large-scale, bulk motions of the interstellar gas, resulting
in substantial gravitational potential fluctuations and a consequent
reduction in the central matter density, bringing the theoretical
predictions in agreement with observations.
* To whom correspondence should be addressed. E-mail: syam{at}physics.mcmaster.ca
