A Multiwavelength Survey of Wolf-Rayet Nebulae in the Large Magellanic Cloud

TL;DR

This study provides a comprehensive multiwavelength analysis of Wolf-Rayet stars in the Large Magellanic Cloud, revealing environmental characteristics, bubble sizes, and evolutionary insights, with implications for understanding massive star evolution in different regions.

Contribution

It offers the first detailed multiwavelength survey of LMC WR stars, analyzing their environments, bubble formations, and associations, highlighting differences between regions like 30 Dor and the rest of the LMC.

Findings

12% of WR stars have small bubbles (<50 pc), mostly WN stars.

WR stars in 30 Dor differ significantly from those elsewhere in the LMC.

Most small bubbles are not in OB associations.

Abstract

Surveys of Wolf-Rayet (WR) stars in the Large Magellanic Cloud (LMC) have yielded a fairly complete catalog of 154 known stars. We have conducted a comprehensive, multiwavelength study of the interstellar/circumstellar environments of WR stars, using the Magellanic Cloud Emission Line Survey (MCELS) images in the H$\alpha$, [O III], and [S II] lines; Spitzer Space Telescope 8 and 24 $\mu$m images; Blanco 4m Telescope H$\alpha$ CCD images; and Australian Telescope Compact Array (ATCA) + Parkes Telescope H I data cube of the LMC. We have also examined whether the WR stars are in OB associations, classified the H II environments of WR stars, and used this information to qualitatively assess the WR stars' evolutionary stages. The 30 Dor giant H II region has active star formation and hosts young massive clusters, thus we have made statistical analyses for 30 Dor and the rest of the LMC both separately and altogether. Due to the presence of massive young clusters, the WR population in 30 Dor is quite different from that from elsewhere in the LMC. We find small bubbles ($<$50 pc diameter) around $\sim$12% of WR stars in the LMC, most of which are WN stars and not in OB associations. The scarcity of small WR bubbles is discussed. Spectroscopic analyses of abundances are needed to determine whether the small WR bubbles contain interstellar medium or circumstellar medium. Implications of the statistics of interstellar environments and OB associations around WR stars are discussed. Multiwavelength images of each LMC WR star are presented.