Supernova-driven turbulent metal mixing in high redshift galactic disks: metallicity fluctuations in the interstellar medium and its imprints on metal poor stars in the Milky Way

Kavli Affiliate: Risa H. Wechsler

| First 5 Authors: Anne Noer Kolborg, Davide Martizzi, Enrico Ramirez-Ruiz, Hugo Pfister, Charli Sakari

| Summary:

The extent to which turbulence mixes gas in the face of recurrent infusions
of fresh metals by supernovae (SNe) could help provide important constraints on
the local star formation conditions. This includes predictions of the
metallicity dispersion amongst metal poor stars, which suggests that the
interstellar medium (ISM) was not very well mixed at these early times. The
purpose of this Letter is to help isolate via a series of numerical experiments
some of the key processes that regulate turbulent mixing of SN elements in
galactic disks. We study the gas interactions in small simulated patches of a
galaxy disk with the goal of resolving the small-scale mixing effects of metals
at parsec scales. By investigating the statistics of variations of $alpha$
elements in these simulations we are able to derive meaningful constraints on
the star formation history (SFH) of the Milky Way (MW). We argue that the
observed dispersion in stellar abundances of metal poor halo stars are
naturally explained by star formation conditions expected in dwarf satellites
or in an early low starforming MW progenitor. Metal variations in phase-mixed
stars give further credence to the idea that the MW halo could have been
assembled primarily by disrupted dwarf satellites.

| Search Query: ArXiv Query: search_query=au:”Risa H. Wechsler”&id_list=&start=0&max_results=10

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