The Hot ISM of Chemically Unevolved Galaxies

Blue compact dwarf (BCD) galaxies are the least chemically evolved gasrichgalaxies in the universe. They are thus excellent laboratories for studyingphysical processes which occurred in the galaxy formation era, when the gas wasmetaldeficient. We wish to obtain deep EPIC spectroscopy to study the evolutionof the hot phase medium in 3 BCDs, IZw49, Mrk 71 and VIIZw403. The first twoBCDs are cometarylike, with propogating star formation along their stellarbodies which allows us to study the time evolution of the hot phase within thesame galaxy. The third BCD allows us to study a .blow out., when the supernovaenergy has disrupted the HI envelope and set up a galactic wind. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]