Marvelous Metals: Surveying the Circumgalactic Medium of Simulated Dwarf Galaxies

Dwarf galaxies are uniquely sensitive to feedback processes and known to experience substantial mass and metal loss from their disks. Here, we investigate the circumgalactic medium (CGM) of 64 isolated dwarf galaxies (6.0 200c reside in the CGM, with ∼70% of CGM mass existing in a warm gas phase, 104.5 < T < 105.5 K, that dominates beyond r/R200c ∼ 0.5. The warm and cool (104.0 < T < 104.5 K) gas phases each retain 5%–10% of metals formed by the dwarf galaxy. The significant fraction of mass and metals residing in the warm CGM phase provides an interpretation for the lack of z ∼ 0 low ion detections beyond b/R200c ∼ 0.5, as the majority of mass in this region exists in higher ions. We find a weak correlation between galaxy mass and total CGM metal retention despite the fraction of metals lost from the halo increasing from ∼10% to >40% toward lower masses. Our findings highlight the CGM (particularly its warm phase) as a key reservoir of mass and metals for dwarf galaxies across stellar masses, underscoring its importance in understanding the baryon cycle in the low-mass regime. Finally, we provide individual simulated galaxy properties and quantify the fraction of UV-observable mass to support future observational programs aimed at performing a metal budget around dwarf galaxies.