Association between Recurrent Novae and Nova Super-Remnants

TL;DR

This paper reviews the current understanding of nova super-remnants (NSRs), highlighting recent discoveries of new Galactic NSRs and a survey in nearby galaxies, advancing knowledge of their formation and prevalence.

Contribution

It presents the first survey for NSRs in external galaxies and reports the discovery of two new Galactic NSRs, expanding the known population.

Findings

Discovery of two new Galactic NSRs.

Initiation of a survey in Andromeda and LMC.

Modelling of evolving NSRs including 12a.

Abstract

Nova super-remnants (NSRs) are substantially extended structures (up to ~130 parsecs across) encompassing recurrent novae. NSRs grow as a result of frequent nova eruptions transporting vast quantities of the locally surrounding interstellar medium away from the binary system over many millennia into a thin high-density shell, as the central white dwarf grows towards the Chandrasekhar limit. The prototypical NSR, first identified as such in 2014, is situated in the Andromeda Galaxy and belongs to the annually erupting nova, M31N 2008-12a (or '12a'). In this short review, modelling of evolving NSRs (including the 12a NSR) will be outlined as motivation towards searching for more of these phenomena in the Galaxy and beyond. The latest developments in this upcoming subfield of nova research will then be presented including the discovery of two new Galactic nova super-remnants (and their consequent modelling) and the first survey undertaken with the sole purpose of finding NSRs in the Andromeda Galaxy and the Large Magellanic Cloud.