A Study of Active Galactic Nuclei in Low Surface Brightness Galaxies
  with Sloan Digital Sky Survey Spectroscopy
  Active galactic nuclei (AGN) in low surface brightness galaxies (LSBGs) have
received little attention in previous studies. In this paper, we present
detailed spectral analysis of 194 LSBGs from the Impey et al. (1996) APM LSBG
sample which have been observed spectroscopically by the Sloan Digital Sky
Survey Data Release 5 (SDSS DR5). Our elaborate spectral analysis enables us to
carry out, for the first time, reliable spectral classification of nuclear
activities in LSBGs based on the standard emission line diagnostic diagrams in
a rigorous way. Star-forming galaxies are common, as found in about 52% LSBGs.
We find, contrary to some of the previous claims, that the fraction of galaxies
containing an AGN is significantly lower than that found in nearby normal
galaxies of high surface brightness. This is qualitatively in line with the
finding of Impey et al. (2001). This result holds true even within each
morphological type from Sa to Sc. LSBGs having larger central stellar velocity
dispersions, or larger physical sizes, tend to have a higher chance to harbor
an AGN. For three AGNs with broad emission lines, the black hole masses
estimated from the emission lines are broadly consistent with the well known
M-$\sigma_\ast$ relation established for normal galaxies and AGNs.
