A search and modeling of peculiar narrow transient line components in novae spectra

In this paper we discuss the formation of peculiar narrow emission line components observed in the spectra of a few novae. We aim to identify the physical source responsible for transient narrow components that present orbital radial velocity modulations, first observed in the post-outburst recombination lines of Nova U Sco 2010. A search for candidate novae showing similar narrow components is presented. Photoionization simulations indicate that the forming region cannot be restricted to the primary Roche Lobe, but could be located around the outer Lagrangian point L3. Further analysis disfavors an origin at the accretion disk and the companion star. In addition, we analyze possible correlations between the presence of the narrow components, the basic nova parameters and the spectral classification in the initial permitted phase.