Date of Award
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Physics and Astronomy
Committee Chair
Stephen A. Walker
Committee Member
Ming Sun
Committee Member
Max Bonamente
Committee Member
Richard Lieu
Research Advisor
Stephen A. Walker
Subject(s)
Galaxies--Clusters, Plasma astrophysics, X-ray astronomy
Abstract
Galaxy Clusters are the largest virialized structures in the universe, with the majority of baryonic matter being made up of the intracluster medium (ICM), a diffuse plasma between the galaxies in the cluster. The large mass of galaxy clusters heats up the ICM to high temperatures, causing it to emit x-rays. When a cluster is left unperturbed, the center of a cluster cools at a faster rate than the outer regions due to the increased mass density and rate of x-ray production. At a later time, after the center of the cluster has had enough time to cool, another cluster is introduced into the system, moving relative to our original cluster at a large impact parameter such that both systems will not collide head on. In these scenarios, the ICM is attracted toward the incoming mass. When the passing cluster leaves interaction range, the mass then falls back onto the cluster, swirling around the center, or sloshing. During this process, the cold ICM in the center of the cluster is pulled out and begins sloshing, however the amount of time this process took is not enough to heat the plasma up. As such, this creates A region of colder plasma through regions of hot plasma, which we call a cold front. RXJ2014.8-2430 is a cluster where multiple sloshing cold fronts have been ii identified within the cluster already in previous observations. Most cold fronts have been observed near the bright cluster cores, however RXJ2014.8-2430 is one of a small group of clusters where cold fronts have been identified out past 500 kpc from the cluster core into the outskirts. Our data uses 190 ks of exposure time from the Chandra X-ray Observatory, which allows us to better resolve features further out in the cluster from the core where less photons are emitted. We provide a detailed analysis of the cold fronts in the cluster, measuring the density-temperature relation in the cold fronts as well as the widths of the cold fronts along their length. We also observe a large concave structure in the ICM in the outskirts of the cluster. This region is consistent with a giant KHI, however could also be the inner rim of a massive gas cavity created from an Active Galactic Nuclei (AGN), and we will show our current work on distinguishing the two scenarios.
Recommended Citation
Sundquist, Matthew, "Large scale cold fronts in sloshing galaxy clusters" (2026). Dissertations. 480.
https://louis.uah.edu/uah-dissertations/480