The impact of pre-supernova feedback and its dependence on environment

Abstract

Integral field units enable resolved studies of a large number of star-forming regions across entire nearby galaxies, providing insight on the conversion of gas into stars and the feedback from the emerging stellar populations over unprecedented dynamic ranges in terms of spatial scale, star-forming region properties, and environments. We use the VLT/MUSE legacy data set covering the central 35 arcmin 2 (∼12 kpc 2 ) of the nearby galaxy NGC 300 to quantify the effect of stellar feedback as a function of the local galactic environment. We extract spectra from emission line regions identified within dendrograms, combine emission line ratios and line widths to distinguish between H II regions, planetary nebulae, and supernova remnants, and compute their ionised gas properties, gas-phase oxygen abundances, and feedback-related pressure terms. For the H II regions, we find that the direct radiation pressure (𝑃 dir ) and the pressure of the ionised gas (𝑃 H II ) weakly increase towards larger galactocentric radii, i.e. along the galaxy's (negative) abundance and (positive) extinction gradients. While the increase of 𝑃 H II with galactocentric radius is likely due to higher photon fluxes from lower-metallicity stellar populations, we find that the increase of 𝑃 dir is likely driven by the combination of higher photon fluxes and enhanced dust content at larger galactocentric radii. In light of the above, we investigate the effect of increased pre-supernova feedback at larger galactocentric distances (lower metallicities and increased dust mass surface density) on the ISM, finding that supernovae at lower metallicities expand into lower-density environments, thereby enhancing the impact of supernova feedback.

Comparing the pre-SNe feedback and environmental pressures for 6000 HII regions across 19 nearby spiral galaxies

“…Rugel et al 2019;Watkins et al 2019; Barnes et al 2020;Olivier et al 2021), the Small and Large Magellanic Clouds (Oey 1996a,b;Lopez et al 2011Lopez et al , 2014Pellegrini et al 2010Pellegrini et al , 2012Chevance et al 2016;McLeod et al 2019), and in nearby galaxies (e.g. McLeod et al 2020McLeod et al , 2021.…”

Dust Grain Growth and Dusty Supernovae in Low-metallicity Molecular Clouds

“…They are also interesting since an increased presupernova feedback (harder ionizing radiation and increased photon fluxes) is expected in low-metallicity environments (e.g. McLeod et al 2021). We will consider the potential well of the molecular cloud and the star cluster, the growth of grains originally residing within clumps, as well as dust grains produced in multiple pair-instability and core-collapse supernova explosions.…”