X-ray Sources in Metal Poor Dwarf Galaxies

Unexpectedly hard continua in the extreme ultraviolet is produced in some metal-poor dwarf galaxies. To determine if this hard continuum is substantially due to accreting compact objects, we take a sample of seven Chandra X-ray observations of nearby, metal-poor, star-forming, dwarf galaxies with strong nebular He II (λ4686) emission that do not show spectroscopic signatures from Wolf-Rayet stars. We find that only two of our observations contain ultraluminous X-ray sources. We conclude that in the majority of metal-poor dwarfs, X-ray sources are probably unlikely to produce the extreme ultraviolet continuum. In the future, we hope to add a dozen more archival Chandra observations to improve the statistics of this survey.