# Physical properties of superbubbles in the Antennae galaxies

## TL;DR

This study detects and analyzes superbubbles in the Antennae galaxies using high-resolution observations, estimating their physical properties and validating results with hydrodynamic simulations, revealing insights into star feedback and ionization sources.

## Contribution

First detailed detection and physical characterization of superbubbles in the Antennae galaxies using Fabry-Pérot interferometry and hydrodynamic modeling.

## Key findings

- Superbubbles are centered on bright HII regions, especially in the overlap area.
- Hydrodynamic simulations successfully reproduce observed superbubbles.
- Ionization is mainly from stars, with some supernova shock influence.

## Abstract

Mass outflow generated by the dynamical feedback from massive stars is currently a topic of high interest. Using a purpose-developed analysis technique, and taking full advantage of the high kinematic and angular resolution of our instrument we have detected a number of expanding superbubbles in the interacting pair of galaxies Arp 244 (NGC 4038/9) commonly known as the Antennae. We use a Fabry-P\'erot interferometer GH{\alpha}FaS to measure the profile of H{\alpha} in emission over the full extent of the object, except for the extended HI tails. The superbubbles are found centred on most of the brightest HII regions, especially in the overlap area of the two merging galaxies. We use measured sizes, expansion velocities and luminosities of the shells to estimate most of the physical parameters of the bubbles, including the kinetic energy of the expansion. In order to assess the validity of our results and approximations we perform a hydrodynamic simulation and manage to reproduce well our best measured superbubble with reasonable physical input assumptions. We also study the sources of ionization of the shells, finding that at the current, quite late stage of expansion, radiation from the remaining stars dominates, though the effect of supernova shocks can still be noted.