Confirmation of Dwarf Stellar Halos Built by Accretion at the dwarf galaxy scale (Fielder)
Type: Talk
Session: Galaxy Morphology and Low Surface Brightness Features
Author: Catherine Fielder
Abstract: I present deep optical observations of the stellar halo of NGC 300, an LMC-mass system, acquired through the Blanco DECam DELVE-DEEP sub-survey. Analysis reveals a significant discovery: a large, low surface brightness stellar stream extending more than 35 kpc from the galaxy’s center, northward, in addition to other shell structures and a potential stream wrap. While it is well established that stellar halos and substructures reflective of accretion history exist at the Milky Way-mass scale, it remains unclear whether dwarf galaxies harbor similar structures and whether these halos form through accretion or in situ processes such as star formation-driven radial migration. These findings mark the first evidence supporting accretion as a viable mechanism for forming stellar halos in the LMC-mass range beyond the Local Group, shedding light on the intricate dynamics of dwarf galaxy evolution. This work serves as a precursor for the discoveries that will be possible in the southern sky with Rubin Observatory.