Kavli Affiliate: Alexander P. Ji
| First 5 Authors: Martin P. Rey, Martin P. Rey, , ,
| Summary:
We study the stellar mass-iron metallicity relation of dwarf galaxies in the
new high-resolution MEGATRON cosmological radiation-hydrodynamics simulations.
These simulations model galaxy formation up to $zapprox8$ in a region that
will collapse into a Milky-Way-like galaxy at $z=0$, while self-consistently
tracking Population III and II (Pop.~III, Pop.~II) star formation, feedback and
chemical enrichment. MEGATRON dwarf galaxies are in excellent agreement with
the observed stellar mass-metallicity relation at $z=0$, including an
over-abundance of dwarfs along a flat plateau in metallicity ($langle
[rmFe/rmH] rangle approx -2.5$) at low stellar masses ($M_star leq
10^5 , rmM_odot$). We tie this feature to the chemical enrichment of
dwarf galaxies by Pop.~III pair-instability supernova (PISN) explosions. The
strong Lyman-Werner background (LW) from the protogalaxy ensures that PISNe
occur in haloes massive enough ($approx 10^7, rmM_odot$) to retain
their ejecta. We also predict a tail of $approx 20%$ of iron-deficient
($langle [rmFe/rmH] rangle leq – 3$) dwarf galaxies. We show that both
plateau and tail (i) are robust to large variations in Pop.~II feedback
assumptions, and (ii) survive in bound satellites surrounding the central
galaxy at $z=0$.
| Search Query: ArXiv Query: search_query=au:”Alexander P. Ji”&id_list=&start=0&max_results=3