Ultra-Luminous x-Ray Sources in the Most Metal-Poor Galaxies

There is growing observational and theoretical evidence to suggest that Ultra-Luminous X-ray sources {ULX} form preferentially in low metallicity environments. Here we propose a survey of 27 nearby {< 30Mpc} star-forming Extremely Metal Poor Galaxies {Z<5% solar}. There are almost no X-ray observations of such low abundance galaxies {3 in the Chandra archive}. These are the most metal-deficient galaxies known, and a logical place to find ULX if they favor metal-poor systems. We plan to test recent population synthesis models which predict that ULX should be very numerous in metal-poor galaxies. We will also test the hypothesis that ULX form in massive young star clusters, and ask for HST time to obtain the necessay imaging data.