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.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science