Wolf-Rayet stars in the Antennae unveiled by MUSE

TL;DR

This study uses VLT/MUSE data to identify and classify Wolf-Rayet stars in the Antennae galaxies, estimating over 4000 WR stars and analyzing their population ratios to inform stellar evolution models.

Contribution

It provides the first detailed census and classification of Wolf-Rayet stars in the Antennae galaxies using integral field spectroscopy data.

Findings

Estimated total WR stars: 4053 ± 84

WNL and WC types are nearly equal in number

WC/WN ratio aligns with single star evolution models

Abstract

We present the analysis of archival Very Large Telescope (VLT) Multi Unit Spectroscopic Explorer (MUSE) observations of the interacting galaxies NGC 4038/39 (a.k.a. the Antennae) at a distance of 18.1 Mpc. Up to 38 young star-forming complexes with evident contribution from Wolf-Rayet (WR) stars are unveiled. We use publicly available templates of Galactic WR stars in conjunction with available photometric extinction measurements to quantify and classify the WR population in each star-forming region, on the basis of its nearly Solar oxygen abundance. The total estimated number of WR stars in the Antennae is 4053 $\pm$ 84, of which there are 2021 $\pm$ 60 WNL and 2032 $\pm$ 59 WC-types. Our analysis suggests a global WC to WN-type ratio of 1.01 $\pm$ 0.04, which is consistent with the predictions of the single star evolutionary scenario in the most recent BPASS stellar population synthesis models.