Ionized Gas in the NGC 5253 Supernebula:High Spatial and Spectral Resolution Observations with the JVLA and TEXES

TL;DR

This study uses high-resolution JVLA and TEXES observations to analyze the ionized gas in the NGC 5253 supernebula, revealing complex gas structures and velocity components related to star cluster formation.

Contribution

It provides the first high-resolution imaging of ionized gas and fine-structure emission in the supernebula, uncovering detailed gas morphology and kinematics.

Findings

Ionized gas extends in arms or jets from the cluster.

The gas has two components offset in space and velocity.

Possible mechanisms include jets or subcluster infall.

Abstract

The youngest, closest and most compact embedded massive star cluster known excites the supernebula in the nearby dwarf galaxy NGC 5253. It is a crucial target and test case for studying the birth and evolution of the most massive star clusters. We present observations of the ionized gas in this source with high spatial and spectral resolution. The data includes continuum images of free-free emission with ~0.15'' resolution made with the JVLA at 15, 22 and 33 GHz, and a full data cube of the [SIV]10.5 micron fine-structure emission line with ~4.5 km/s velocity resolution and 0.3'' beam, obtained with TEXES on Gemini North. We find that 1) the ionized gas extends out from the cluster in arms or jets, and 2) the ionized gas comprises two components offset both spatially and in velocity. We discuss mechanisms that may have created the observed velocity field; possibilities include large-scale jets or a subcluster falling onto the main source.