OGLE Atlas of Classical Novae. II. Magellanic Clouds

TL;DR

This study analyzes 16 years of OGLE survey data to characterize classical nova populations in the Magellanic Clouds, revealing higher nova rates per unit luminosity than other galaxies, linked to their star formation history.

Contribution

It provides the first systematic measurement of nova rates in the Magellanic Clouds and discusses their implications for galaxy star formation history.

Findings

Nova rates: 2.4 ± 0.8 yr⁻¹ in LMC and 0.9 ± 0.4 yr⁻¹ in SMC

K-band luminosity-specific nova rates are 2-3 times higher than in other galaxies

Discovery of a system mimicking recurrent nova eruptions

Abstract

The population of classical novae in the Magellanic Clouds was poorly known because of a lack of systematic studies. There were some suggestions that nova rates per unit mass in the Magellanic Clouds were higher than in any other galaxy. Here, we present an analysis of data collected over 16 years by the OGLE survey with the aim of characterizing the nova population in the Clouds. We found 20 eruptions of novae, half of which are new discoveries. We robustly measure nova rates of $2.4 \pm 0.8$ yr$^{-1}$ (LMC) and $0.9 \pm 0.4$ yr$^{-1}$ (SMC) and confirm that the K-band luminosity-specific nova rates in both Clouds are 2-3 times higher than in other galaxies. This can be explained by the star formation history in the Magellanic Clouds, specifically the re-ignition of the star formation rate a few Gyr ago. We also present the discovery of the intriguing system OGLE-MBR133.25.1160 which mimics recurrent nova eruptions.