Halo white dwarfs and the hot intergalactic medium

We describe the formation of hot intergalactic gas along with baryonic remnants in the halo. In this scenario, the mass and metallicity of the hot intracluster gas relates directly to the production of baryonic remnants during the collapse of the galactic halos. We construct a schematic but self-consistent model in which early bursts of star formation lead to a large remnant population in the halo, and to the outflow of stellar ejecta into the halo and ultimately the Local Group. This study suggests that the microlensing objects in the halo may predominantly be ∼ 0.5M_⊙ white dwarfs, assuming the initial mass function for early star formation favored the formation of intermediate mass stars with m ≳ 1M_⊙.