Most of the Baryons in Galaxies

Galaxies are missing most of their baryons when compared to the cosmologicalbaryon to dark matter ratio. The Milky Way is missing 2/3 of its baryons andless massive galaxies have retained less than 10% of their baryons. Theorysuggests that these baryons were expelled by intense galactic winds during theprimary star formation period. These galactic winds carry gas far beyond thevirial radius of small and modest galaxies, but the most massive galaxies shouldretain much of this material. e propose to test this picture by searching forthe missing baryons surrounding the most massive spiral galaxy, UGC 12591, afairly isolated galaxy with a rotational velocity of almost 500 km/sec. Ifsuccessful, we will detect a significant fraction of the 5E11 Msun of its missing baryons. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]