Measurements of the Expansion Velocities of Ionized-Gas Superbubbles in Nearby Galaxies Based on Integral Field Spectroscopy Data

TL;DR

This paper introduces a new method to measure the expansion velocities of ionized-gas superbubbles in nearby galaxies using integral field spectroscopy data, overcoming resolution limitations and validated on IC 1613.

Contribution

The paper develops an adaptable technique for estimating bubble expansion velocities from velocity dispersion variations, applicable to various spectrographs and validated on a supernova remnant.

Findings

The method successfully measures the expansion velocity of superbubbles.

Estimated age of the supernova remnant aligns with X-ray data.

Applicable to different integral field spectrographs.

Abstract

The study of the dynamic properties of bubbles in the interstellar medium is important for understanding the feedback mechanisms from star-formation processes in galaxies. The ongoing integral field spectroscopy of nearby star-forming galaxies reveals many expanding bubbles and superbubbles identified by the local increase in gas velocity dispersion. The limited angular resolution often prevents bona fide measures of the expansion velocities in galaxies outside the Local Group, even despite sufficient spectroscopic resolution. We present a method that makes it possible to measure the expansion velocity of bubbles surrounding massive stars and clusters based on the data about local variations in gas velocity dispersion. We adapt the method for the Fabry-Perot interferometers used with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences, as well as for any integral field spectrograph with a Gaussian line spread function. We apply the method described to analyze the kinematics of ionized superbubbles gas and the only known supernova remnant in the IC 1613 galaxy. The estimate of the kinematic age of the supernova remnant (on the order of 3100 years) agrees well with the previously obtained independent estimate based on X-ray data.