Abstract
The dynamical impact of Lyman-alpha (Ly\alpha) radiation pressure on galaxy
formation depends on the rate and duration of momentum transfer between
Ly\alpha photons and neutral hydrogen gas. Although photon trapping has the
potential to multiply the effective force, ionizing radiation from stellar
sources may relieve the Ly\alpha pressure before appreciably affecting the
kinematics of the host galaxy or efficiently coupling Ly\alpha photons to the
outflow. We present self-consistent Ly\alpha radiation-hydrodynamics
simulations of high-$z$ galaxy environments by coupling the Cosmic Ly\alpha
Transfer code (COLT) with spherically symmetric Lagrangian frame hydrodynamics.
The accurate but computationally expensive Monte-Carlo radiative transfer
calculations are feasible under the one-dimensional approximation. In certain
cases Ly\alpha feedback significantly enhances the velocity of the shell of
gas expanding around a central source. Radiative feedback alone is capable of
ejecting baryons into the intergalactic medium (IGM) for protogalaxies with a
virial mass of $M_vir 10^8~M_ødot$. We compare the
Ly\alpha signatures of Population III stars with $10^5$ K blackbody emission
to that of direct collapse black holes with a nonthermal Compton-thick spectrum
and find substantial differences. For both sources, the flux emerging from the
galaxy is reprocessed by the IGM such that the observed Ly\alpha luminosity
is reduced significantly and the time-averaged velocity offset of the
Ly\alpha peak is shifted redward.
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