A Plethora of AGN Among Lyman Alpha Galaxies at Low Redshift
  We investigate the fraction of z ~ 0.3 Lyman alpha emitting galaxies (LAEs)
which host active galactic nucleus activity, which is typically from 1 - 5% at
2 < z < 6. Using optical spectroscopy of 23 LAEs at 0.2 < z < 0.45 selected
with GALEX UV data, we probe for AGN with a variety of methods, including line
widths, diagnostic line ratios, high-ionization emission, infrared activity and
X-ray luminosity. We found that our sample of low-redshift LAEs has an AGN
fraction of 43 ^{+18}{-26}%, significantly higher than at high redshift. While
previous results have shown that low-redshift LAEs have a lower space density
than their high-redshift analogs, these results show that star-forming LAEs at
low-redshift are rarer still. Accounting for differences in available AGN
classification methods, we conclude that rest-frame optical spectroscopy is
necessary to identify low-luminosity AGNs in LAEs at high redshift, and that
limits on the X-ray flux are necessary to determine the extent to which the AGN
contaminates the Lyman alpha fluxes.
