Discipline: Technology and Engineering
Subcategory: Astronomy and Astrophysics
Bazit Bisiolu - Farmingdale State College
Co-Author(s): Dr. Edmund Douglass
Galaxy clusters are the largest known gravitationally bound structures in the universe. Comprised of hundreds to thousands of galaxies they are formed through the continuous accumulation of smaller systems and are bound together by the gravity of a large dark matter halo. These clusters contain a form of super-heated X-ray emitting plasma known as the intracluster medium (ICM). The ICM makes up the majority of the baryonic matter of a cluster and extends from the core to the cluster outskirts. Formation history of galaxy clusters can be probed by analyzing both the optical light from the galaxies themselves as well as the X-ray light from the ICM. Those clusters with disturbed X-ray morphologies consistent with ongoing mergers should display optical evidence of two or more systems interacting.
We have examined a large sample of galaxy clusters observed by the Chandra X-ray Observatory and Sloan Digital Sky Survey (SDSS). We produced residual images of excess X-ray gas by fitting and then subtracting a 2-D elliptical model of cluster emission. This has allowed us to identify ICM substructure resulting from any ongoing mergers. Using optical data from SDSS, we have analyzed the spatial and velocity distribution of galaxies in each cluster to characterize their dynamical state. The two merger analysis methods were then compared.
Through observation and analysis of this data we gain a better understanding of the history and formation of galaxy clusters. Studying these giant systems provides us with the opportunity to probe the behavior of matter on the largest of scales.
Funder Acknowledgement(s): Research is funded by Farmingdale State College, the Collegiate Science and Technology Entry Program and LSAMP.
Faculty Advisor: Dr. Edmund Douglass, douglae@Farmingdale.edu
Role: Analyses of X-ray emissions for a large sample of around 30 galaxy clusters. Gathering, categorizing, calculating and plotting the location, redshifts, and velocities of each galaxy in the specific clusters in order to asses the merger states that they may be in. The writing and use of programs in python that are used to take data from the Chandra X-ray Observatory and transfer them into a form that can be observed and studied.