2012MNRAS.423.1144R

We study the possibility that the very broad ( ∼ 1500 km/s) and luminous (L₅₀₀₇ ∼ 1.4 {x} 10³⁷ erg/s) [O III] line emission observed in the globular cluster RZ 2109 might be explained with the photoionization of nova ejecta by the bright (L_X ∼ 4 {x} 10³⁹ 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 ( ≳ 0.5 {x} 10^–3 M_☉), 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.