Ha Emission from the Magellanic Bridge

TL;DR

This study analyzes H-alpha emission in the Magellanic Bridge, revealing a quiescent, sparsely ionized interstellar medium with weak emission regions, and finds correlations with molecular and atomic hydrogen structures.

Contribution

It provides the first detailed analysis of H-alpha emission in the Magellanic Bridge, highlighting the ISM's low activity and its relation to molecular and atomic gas structures.

Findings

H-alpha emission regions are small, weak, and sparsely distributed.

The ISM in the Magellanic Bridge is relatively quiescent and inactive.

H-alpha emission correlates with CO and HI features.

Abstract

We present here a preliminary report and commentary of recently processed observations of Ha emission towards the Magellanic Bridge. These data have been analysed in an attempt to quantify the extent to which the stellar population is capable of reshaping the local ISM. We find that the Ha emission regions are small, weak and sparsely distributed, consistent with a relatively quiescent and inactive ISM where radiative and collisional ionisation is inefficient and sporadic. This suggests that energetic processes at the small scale (i.e. ~tens of pc) do not dominate the energy balance within the ISM of the Bridge, which therefore hosts a pristine turbulent structure, otherwise inaccessible within our own Galaxy. We find Ha emission that is well correlated with detected 12CO(1-0) line emission (a proxy for molecular hydrogen), as well as other easily identified ring-like HI features.