Nearby ULX in metal-poor environment as cosmological laboratories

Supermassive black holes (SMBHs) at redshift z>7 pose a serious challenge toour understanding of black hole (BH) formation and evolution. Most likely SMBHsat high redshift require massive seed black holes (BHs) (10^5 solar masses)created in the gravitational collapse of large gas clouds with subsequentmerging. We propose to observe 8 extreme metalpoor blue compact dwarf galaxies,which are the best (local) laboratory for massive BH seed formation and starformation under low metallicity conditions. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]