Hubble Space Telescope Imaging of the Active Dwarf Galaxy RGG 118
  RGG 118 (SDSS 1523+1145) is a nearby ($z=0.0243$), dwarf disk galaxy
($M_{\ast}\approx2\times10^{9} M_{\odot}$) found to host an active $\sim50,000$
solar mass black hole at its core (Baldassare et al. 2015). RGG 118 is one of a
growing collective sample of dwarf galaxies known to contain active galactic
nuclei -- a group which, until recently, contained only a handful of objects.
Here, we report on new \textit{Hubble Space Telescope} Wide Field Camera 3 UVIS
and IR imaging of RGG 118, with the main goal of analyzing its structure. Using
2-D parametric modeling, we find that the morphology of RGG 118 is best
described by an outer spiral disk, inner component consistent with a
pseudobulge, and central PSF. The luminosity of the PSF is consistent with the
central point source being dominated by the AGN. We measure the luminosity and
mass of the "pseudobulge" and confirm that the central black hole in RGG 118 is
under-massive with respect to the $M_{BH}-M_{\rm bulge}$ and $M_{BH}-L_{\rm
bulge}$ relations. This result is consistent with a picture in which black
holes in disk-dominated galaxies grow primarily through secular processes.
