Broad [OIII] in the globular cluster RZ 2109: X-ray ionized nova ejecta?
  We study the possibility that the very broad (~1500 km/s) and luminous
(L_5007 ~ 1.4e37 erg/s) [OIII] line emission observed in the globular cluster
RZ 2109 might be explained with the photoionization of nova ejecta by the
bright (L_X ~ 4e39 erg/s) X-ray source hosted in the same globular cluster. We
find that such scenario is plausible and explains most of the features of the
RZ 2109 spectrum (line luminosity, absence of H emission lines, peculiar
asymmetry of the line profile); on the other hand, it requires the nova ejecta
to be relatively massive (>~ 0.5e-3 Msun}), and the nova to be located at a
distance <~ 0.1 pc from the X-ray source. We also predict the time evolution of
the RZ 2109 line emission, so that future observations can be used to test this
scenario.
