Investigating the Oxygen Abundance of the M101 Group with Deep Narrowband Imaging

Abstract

How do galaxies evolve? This is at first a seemingly simple and fundamental question, yet it is a question laced with intricacies. To help unravel the mystery of galaxy evolution, I present deep, narrowband imaging of the nearby spiral galaxy M101 and its satellites. Although the M101 Group is a relatively poor group with only one major member, it is a dynamic group! M101 itself is thought to have interacted with its most massive satellite ~300 Myr ago. Using narrowband images targeting key emission lines (Hα, Hβ, [OIII]λλ4959,5007, and [OII]λ3727), I investigate how this interaction might have influenced the oxygen abundances of the M101 Group. Importantly, this survey represents the highest number of oxygen abundances estimated for M101 totaling ~650 HII regions in M101 alone! Investigating the shape of the radial abundance profile, I find tentative evidence for a flattened abundance gradient beyond R ~ 15 kpc, likely caused by a combination of the interaction and M101’s own internal dynamics.

Ray Garner

TAMU Astronomy Postdoctoral Researcher

I’m a scientist, Star Wars fan, and amateur photographer raised in Georgia. My research interests include galaxy evolution, star formation, satellite galaxies, and nebular diagnostics.