HALO WHITE-DWARFS AND BARYONIC DARE MATTER

We describe the formation of hot intergalactic gas along with baryonic remnants in galaxy halos. Tn this scenario, the mass and metallicity of the hot intracluster and intragroup gas relates directly to the pro duction of baryonic remnants during the collapse of 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 Loc al Group. We consider local as well as high redshift constraints on th is scenario. This study suggests that the microlensing objects in the Galactic halo may predominantly be similar to 0.5M. white dwarfs, assu ming that the initial mass function for early star formation favored t he formation of intermediate mass stars with m greater than or similar to 1 M.. However, the bulk of the baryonic dark matter in this scenar io is associated with the ejecta of the white dwarf progenitors, and r esides in the hot intergalactic medium.