On the Origin of Narrow Line Components in Recurrent Novae

The spectral evolution of the recurrent nova U Sco presented conspicuous formation of narrow emission line components in the recombination lines a few days after maximum. The physical origin of these lines and their frequency among classical and recurrent novae have not been well established yet. In this work we identify additional novae showing this phenomenon. On the basis of photoionization modeling we propose that the forming region is not restricted to the primary Roche Lobe.