  We describe our efforts to study dwarf galaxies with active nuclei, whose
black holes, with masses < 10^6 M_sun, provide the best current observational
constraints on the mass distribution of primordial seed black holes. Although
these low-mass galaxies do not necessarily contain classical bulges, Barth,
Greene, & Ho (2005) show that their stellar velocity dispersions and black hole
masses obey the same relation as more massive systems. In order to characterize
the properties of the dwarf hosts without the glare of the active nucleus, we
have compiled a complementary sample of narrow-line active galaxies with
low-mass hosts. The host galaxy properties, both their structures and stellar
populations, are consistent with the general properties of low-mass, blue
galaxies from Sloan. The black holes in these galaxies are probably radiating
close to their Eddington limits, suggesting we may have found Type 2 analogues
of narrow-line Seyfert 1 galaxies.

Astrophysics