How do galaxies evolve over cosmic time?
How do they build and use their gaseous reservoirs?
We probe the circumgalactic medium (CGM), which surrounds every galaxy out to 100 times the size of their stellar disks.
We measure how much gas is there, what it is made of, and how it is moving.
By comparing the gas properties to host galaxy properties, we determine whether and how the gas is accreting onto or outflowing from the galaxies.
What has the group been doing recently?
Amisha Rane presented "Capturing the Baryon Cycle of Galaxies in Action: Exploring Gas Flows at z~0.27" at the OU Graduate College Research Showcase in February 2026.
Ethan Dyer and Sameer presented "Mapping the Invisible Gas Around Galaxies to Trace 10 Billion Years of Galaxy Evolution" at the OU Graduate College Research Showcase in February 2026.
Emily Thrun presented her poster "How Galaxies Breathe: The Giant Invisible Recycling System of the Universe" at the OU Undergraduate Research Day in April 2026.
Everyone had lots of interest in their posters and found the experience useful in explaining their research to non-astronomers!
We published an exciting paper in Nature Astronomy in September 2024, which mapped the CGM in emission around a nearly face-on starbursting galaxy (free access on arXiv.org). It collected quite a bit of media attention, including several tv/radio/podcast interviews with Dr Nielsen!
Cristy Roberts (ANU/ASTRO 3D) created the image (right) for us. A galaxy is located at the center, where outflowing (white), inflowing (blue), and other circumgalactic gas (purple) surrounds it.
If you're looking for MAGIICAT data, you're in luck. It has migrated with us! Click on Trixie the MAGIICAT on the left for a shortcut.