X-RAY DETECTED ACTIVE GALACTIC NUCLEI in DWARF GALAXIES at 0 < z < 1

We present a sample of accreting supermassive black holes (SMBHs) in dwarf galaxies at z < 1. We identify dwarf galaxies in the NEWFIRM Medium Band Survey with stellar masses of M M < 3 10⁹ that have spectroscopic redshifts from the DEEP2 survey and lie within the region covered by deep (flux limit of ∼ 10 × 10 erg cm s^-17 16^-2 1) archival Chandra X-ray data. From our sample of 605 dwarf galaxies, 10 exhibit X-ray emission consistent with that arising from active galactic nucleus (AGN) activity. If black-hole mass scales roughly with stellar mass, then we expect that these AGNs are powered by SMBHs with masses of ∼10¹⁰ 5⁶ - M and typical Eddington ratios of ∼5%. Furthermore, we find an AGN fraction consistent with extrapolations of other searches of ∼0.6% 3% - for 10³ 10⁹ 9 and 0.1 0.6 z . Our AGN fraction is in good agreement with a semi-analytic model, suggesting that, as we search larger volumes, we may use comparisons between observed AGN fractions and models to understand seeding mechanisms in the early universe.