Speaker
Description
Highly mass-loaded outflows from low-mass galaxies are a well-established consequence of ubiquitous implementation of energetic feedback prescriptions into hydrodynamical simulations and are produced by the smallest of galaxies in simulations such as EAGLE and TNG, resulting in mass loadings ($\eta$) between 10 and 100. However the observational literature lacks consensus on the presence of highly mass-loaded outflows from galaxies of similar masses, possibly in part due to the difficult nature of measuring this by observational means. Measurements from EAGLE and TNG disagree with some of the recent observational studies by up to several orders of magnitude, with a recent study (Marasco+23) identifying values in the region of $\eta=0.02$.
Low-mass galaxies are touted as being responsible for the bulk of IGM enrichment (Wiersma+10; Booth+12) as observed through QSO absorption lines. Using Aguirre+02’s Pixel Optical Depth (POD) method (see also Turner+14), Turner+16 produce optical depth statistics from EAGLE to show the relation between metal enrichment and environmental gas density.
We analyse the impact of selectively removing metals from EAGLE according to their source galaxy mass by considering the impact on said statistical relation. By doing so, we can identify whether the lowest mass galaxies contribute significantly to IGM enrichment and whether such galaxies require highly mass-loaded outflows to support this enrichment.
I will be presenting results obtained from both analytical and POD analysis (the latter producing an observable relation) to identify the galaxies responsible for IGM metal enrichment and additionally a commentary on how this analysis can be extended to newer simulations.
