VLA 22 GHz Imaging of Massive Star Formation in Local Wolf-Rayet Galaxies

TL;DR

This study uses 22 GHz VLA imaging to identify and analyze regions of massive star formation in local Wolf-Rayet galaxies, providing a catalog of potential super star clusters for future detailed studies.

Contribution

It presents the first catalog of free-free emission regions in Wolf-Rayet galaxies, enabling extinction-free estimates of star formation properties and identifying candidates for super star clusters.

Findings

92 regions of likely free-free emission identified

39 regions meet criteria for hosting super star clusters

29 regions could contain individual massive SSCs

Abstract

We present 22 GHz imaging of regions of massive star formation within the Local Wolf-Rayet Galaxy Sample (LWRGS), a NSF's Karl G. Jansky Very Large Array (VLA) survey of 30 local galaxies showing spectral features of Wolf-Rayet (WR) stars. These spectral features are present in galaxies with young super star clusters (SSCs), and are an indicator of large concentrations of massive stars. We present a catalog of 92 individually-identified regions of likely free-free emission associated with potential young SSCs located in these WR galaxies. The free-free fluxes from these maps allow extinction-free estimates of the Lyman continuum rates, masses, and luminosities of the emission regions. 39 of these regions meet the minimum Lyman continuum rate to contain at least once SSC, and 29 of these regions could contain individual SSCs massive enough to test specific theories on star formation and feedback inhibition in SSCs, requiring follow-up observations at higher spatial resolution. The resulting catalog provides sources for future molecular line and infrared studies into the properties of super star cluster formation.