We describe new optical images and spectra of POX 52 , a dwarf galaxy with an active nucleus that was originally detected in the POX objective-prism survey .
While POX 52 was originally thought to be a Seyfert 2 galaxy , the new data reveal an emission-line spectrum very similar to that of the dwarf Seyfert 1 galaxy NGC 4395 , with broad components to the permitted line profiles , and we classify POX 52 as a Seyfert 1 galaxy .
The host galaxy appears to be a dwarf elliptical , and its brightness profile is best fit by a Sérsic model with an index of 3.6 \pm 0.2 and a total magnitude of M _ { V } = -17.6 .
Applying mass-luminosity-linewidth scaling relations to estimate the black hole mass from the broad H \beta linewidth and nonstellar continuum luminosity , we find M _ { \mathrm { BH } } \approx 1.6 \times 10 ^ { 5 } ~ { } M _ { \sun } .
The stellar velocity dispersion in the host galaxy , measured from the Ca ii \lambda 8498 , 8542 Å lines , is 36 \pm 5 km s ^ { -1 } , also suggestive of a black hole mass of order 10 ^ { 5 } ~ { } M _ { \sun } .
Further searches for active nuclei in dwarf galaxies can provide unique constraints on the demographics of black holes in the mass range below 10 ^ { 6 } ~ { } M _ { \sun } .