The Contribution of Chemical Abundances in Nova Ejecta to the Interstellar Medium

TL;DR

This study uses Monte Carlo simulations based on nova models to estimate the contribution of nova ejecta to the Galaxy's interstellar medium, focusing on isotopic ratios and element abundances.

Contribution

It provides new estimates of the mass and isotopic contributions of nova ejecta to the Galactic interstellar medium using a Monte Carlo approach.

Findings

Nova ejecta contribute about 10% of $^{13}$C, 5% of $^{15}$N, and 20% of $^{17}$O in the Galaxy.

Isotopic ratios in nova ejecta are about ten times higher than in red giants.

The model's predicted abundances do not fully match observational data.

Abstract

According to the nova model from \citet{Yaron2005} and \citet{Jose1998} and using Monte Carlo simulation method, we investigate the contribution of chemical abundances in nova ejecta to the interstellar medium (ISM) of the Galaxy. We find that the ejected mass by classical novae (CNe) is about $2.7\times10^{-3}$ $ \rm M_\odot\ {\rm yr^{-1}}$. In the nova ejecta, the isotopic ratios of C, N and O, that is, $^{13}$C/$^{12}$C, $^{15}$N/$^{14}$N and $^{17}$O/$^{16}$O, are higher about one order of magnitude than those in red giants. We estimate that about 10$\%$, 5$\%$ and 20$\%$ of $^{13}$C, $^{15}$N and $^{17}$O in the ISM of the Galaxy come from nova ejecta, respectively. However, the chemical abundances of C, N and O calculated by our model can not cover all of observational values. This means that there is still a long way to go for understanding novae.