Related papers: Photoionization Feedback in Low--Mass Galaxies at …
It has been argued that a UV photoionizing background radiation field suppresses the formation of dwarf galaxies, and may even inhibit the formation of larger galaxies. In order to test this, we present gas-dynamical simulations of the…
An ionizing UV background (UVB) inhibits gas accretion and photo-evaporates gas from the shallow potential wells of small, dwarf galaxies. During cosmological reionization, this effect can result in negative feedback: suppressing…
We use three-dimensional hydrodynamic simulations to investigate the effects of a transient photoionizing ultraviolet (UV) flux on the collapse and cooling of pregalactic clouds. These clouds have masses in the range 10^5 -10^7 M_sun, form…
Photoionization by the high-redshift ultraviolet radiation background heats low density gas before it falls into dark matter potential wells, and it eliminates the neutral hydrogen and singly ionized helium that dominate cooling of…
We use high resolution N-body/gasdynamical simulations to investigate the effects of a photoionizing UV background on the assembly of disk galaxies in hierarchically clustering universes. We focus on the mass and rotational properties of…
I use a 1-D Lagrangian code which follows both a gaseous and a dark component to study the effects of a metagalactic UV background on the formation of dwarf galaxies. In the case of an ionising background consistent with the existing…
We explore the impacts of ultraviolet (UV) radiation feedback on galaxies during the epoch of reionisation by cosmological simulations in which hydrodynamics and the transfer of the H and He ionising photons are consistently coupled.…
We find that the amount and nature of the assumed ionizing background can strongly affect galaxy formation and evolution. Galaxy evolution simulations typically incorporate an ultraviolet background which falls off rapidly above z=3; e.g.,…
We investigate the effects of the observed UV background radiation on galaxy formation. Photoionization by UV radiation decreases the cooling rate of the gas in halos, so that objects with only large density contrasts can self-shield…
We present first results from three-dimensional hydrodynamic simulations of the high redshift formation of dwarf galaxies. The simulations use an Eulerian adaptive mesh refinement technique to follow the non-equilibrium chemistry of…
One of the largest uncertainties in understanding the effect of a background UV field on galaxy formation is the intensity and evolution of the radiation field with redshift. This work attempts to shed light on this issue by computing the…
The UV escape fraction from high-redshift galaxies plays a key role in models of cosmic reionisation. Because it is currently not possible to deduce the escape fractions during the epoch of reionisation from observations, we have to rely on…
We use new studies of the cosmic evolution of star-forming galaxies to estimate the production rate of ionizing photons from hot, massive stars at low and intermediate redshifts. The luminosity function of blue galaxies in the Canada-France…
The reionization of the intergalactic medium at redshifts $z\gtrsim 6$ is expected to have a lasting impact on galaxies residing in low-mass dark matter halos. Unable to accrete or retain gas photo-heated to temperatures $T \gtrsim 10^4$ K,…
During the period of reionization the Universe was filled with a cosmological background of ionizing radiation. By that time a significant fraction of the cosmic gas had already been incorporated into collapsed galactic halos with virial…
Recent observations on the cosmic microwave background by Wilkinson Microwave Anisotropy Probe(WMAP) strongly suggest that the reionization of the universe took place quite early (z \sim 17). On the other hand, it has been pointed out that…
The temporal evolution of the ionizing UV background radiation field at high redshift provides a probe of the evolution of the early star formation rate. By comparing the observed levels of absorption in the highest redshift quasar spectra…
The estimate of the ionizing UV background through the proximity effect analysis is discussed. Taking into account the correct bending of the column density distribution which appears in high resolution high s/n data, a value of the UV…
The ionizing ultraviolet background (UVB) during reionization can suppress the gas content of low-mass galaxies, even those capable of efficient atomic cooling, and thus lead to an extended reionization epoch. In this work, we explore the…
Any successful model of galaxy formation needs to explain the low rate of star formation in the small progenitors of today's galaxies. This inefficiency is necessary for reproducing the low stellar-to-virial mass fractions, suggested by…