# Discovery of Molecular and Atomic Clouds Associated with the Magellanic Superbubble 30 Doradus C

## TL;DR

This study uncovers molecular and atomic clouds around the Magellanic superbubble 30 Doradus C, linking gas distributions with X-ray and gamma-ray emissions to understand cosmic-ray acceleration and interaction processes.

## Contribution

It provides the first detailed mapping of molecular and atomic clouds associated with 30 Doradus C and explores their connection to high-energy emissions and cosmic-ray acceleration.

## Key findings

- Five molecular clouds identified in the western shell.
- Enhanced non-thermal X-rays suggest magnetic field amplification.
- Gamma-ray distribution correlates with interstellar proton density.

## Abstract

We analyzed the 2.6-mm CO and 21-cm HI lines toward the Magellanic superbubble 30 Doradus C, in order to reveal the associated molecular and atomic gas. We uncovered five molecular clouds in a velocity range from 251 to 276 km s$^{-1}$ toward the western shell. The non-thermal X-rays are clearly enhanced around the molecular clouds on a pc scale, suggesting possible evidence for magnetic field amplification via shock-cloud interaction. The thermal X-rays are brighter in the eastern shell, where there are no dense molecular or atomic clouds, opposite to the western shell. The TeV $\gamma$-ray distribution may spatially match the total interstellar proton column density as well as the non-thermal X-rays. If the hadronic $\gamma$-ray is dominant, the total energy of the cosmic-ray protons is at least $\sim1.2 \times 10^{50}$ erg with the estimated mean interstellar proton density $\sim60$ cm$^{-3}$. In addition the $\gamma$-ray flux associated with the molecular cloud (e.g., MC3) could be detected and resolved by the Cherenkov Telescope Array (CTA). This should permit CTA to probe the diffusion of cosmic-rays into the associated dense ISM.