Stellar Feedback in Nearby Dwarf Galaxies

(Rowland et al., 2024)

One field of research that I am particularly interested in is the study of nearby, low metallicity dwarf galaxies. These galaxies provide a unique opportunity to study how stars shape their environments in extreme conditions, similar to those of the early Universe.

In this work, we investigate the impact of stellar feedback in three dwarf starburst galaxies — J0921, KKH046, and Leo P. Using VLT/MUSE integral field spectroscopy, we examine the properties of 30 individual HII regions within these galaxies, focusing on their ionised gas and stellar populations. We quantify two pre-supernova stellar feedback mechanisms, namely the direct radiation pressure and photoionisation feedback, and explore how feedback strength varies with HII region properties.

Our findings suggest that stellar feedback decreases as regions evolve, with feedback strength also influenced by the metallicity of the regions. This work extends feedback studies from massive galaxies to low-mass dwarfs, providing insights into how these small systems regulate star formation and evolve over time, offering a glimpse into the processes that shaped galaxies in the early universe.

The three galaxies I studied in this work were observed with the MUSE IFU on the Very Large Telescope (VLT) in Chile.

MUSE is an Integral Field Unit spectrograph, meaning we can take both images and spectra of our targets. Here is a spectrum of one of the HII regions analysed in this work.

Stellar feedback and the size of HII regions

In this paper, we show how the feedback-related pressure terms within HII regions are dependent on properties such as the metallicity (left) and size (right) of the HII regions.

References

2024