The onset of jets in classical novae

TL;DR

This paper reports the detection of jets and accretion disc signatures in two classical novae over 1000 days, supporting models that explain spectral line changes and their role in enriching the interstellar medium.

Contribution

It provides detailed spectroscopic observations of jets and accretion discs in novae, confirming their presence and timing, and discusses implications for nova evolution and interstellar medium enrichment.

Findings

Jets and accretion disc signatures observed in V906 Car and V5668 Sgr.

Timing of spectral features consistent with jet and disc models.

Implications for interstellar medium enrichment discussed.

Abstract

We present two further classical novae, V906 Car and V5668 Sgr, that show jets and accretion disc spectral signatures in their H-alpha complexes throughout the first 1000 days following their eruptions. From extensive densely time-sampled spectroscopy, we measure the appearance of the first high-velocity absorption component in V906 Car, and the duration of the commencement of the main H-alpha emission. We constrain the time taken for V5668 Sgr to transition to the nebular phase using [N II] 6584\r{A}. We find these timings to be consistent with the jet and accretion disc model for explaining optical spectral line profile changes in classical novae, and discuss the implications of this model for enrichment of the interstellar medium.