A Survey of Novae in M83

TL;DR

This survey of novae in galaxy M83 over seven years identified 19 novae, estimated a nova rate of about 19 per year, and found that these novae are more luminous and fade faster than those in M31, indicating a disk population.

Contribution

First synoptic survey of novae in M83 providing nova rate, luminosity-specific rate, and spatial distribution analysis, revealing a disk-dominated nova population.

Findings

Nova rate in M83 is approximately 19 per year.

Novae are more luminous and fade faster than in M31.

Novae are spatially more extended than galaxy light, indicating a disk population.

Abstract

The results of the first synoptic survey of novae in the barred spiral and starburst galaxy, M83 (NGC 5236), are presented. A total of 19 novae and one background supernova were discovered during the course of a nearly seven-year survey comprised of over 200 individual nights of observation between 2012 December 12 and 2019 March 14. After correcting for the limiting magnitude and the spatial and temporal coverage of the survey, the nova rate in M83 was found to be $R=19^{+5}_{-3}$ yr$^{-1}$. This rate, when normalized to the $K$-band luminosity of the galaxy, yields a luminosity-specific nova rate, $\nu_K = 3.0^{+0.9}_{-0.6}\times10^{-10}$ yr$^{-1} L_{\odot,K}^{-1}$. The spatial distribution of the novae is found to be more extended than the overall galaxy light suggesting that the observed novae are likely dominated by a disk population. This result is consistent with the observed nova light curves which reveal that the M83 novae are on average more luminous at maximum light and fade faster when compared with novae observed in M31. Generally, the more luminous M83 novae were observed to fade more rapidly, with the complete sample being broadly consistent with a linear Maximum-Magnitude vs Rate of Decline relation.