Large Halos of Missing Baryons Around Galaxies

If galaxies had the cosmological baryontodark matter ratio, they would have330 times their observed baryon mass. These missing baryons are undetected, butsome fraction may surround a galaxy with a hot diffuse halo extending toR_virial (250 kpc). A loosely bound gaseous halo could be stripped in a clusteror group environment, but should be relatively undisturbed around isolatedlatetype spirals. Existing observations of spirals are mainly of nearbysystems, where only the inner parts fit in a field of view so a halo on thescale of R_virial would pass unnoticed. To detect or place limits on a largehalo of missing baryons, we propose to observe isolated L* spirals sufficientlydistant that we can detect emission to at least R_virial. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]