New insights into galaxy cluster astrophysics using the Suzaku X-ray satellite
Abstract/Contents
- Abstract
- Galaxy clusters enable a broad range of astrophysical studies, from the microphysics of hot tenuous plasmas, to the physics of galaxy evolution, to constraining cosmological models. In particular, much can, and has, been learned from detailed studies of the nearest brightest systems, in which the relevant astrophysics can be viewed "in closeup". The focus of this thesis is the analysis of , and extraction of novel results from, observations of nearby galaxy clusters made with the Suzaku X-ray satellite. In particular, the first part of the thesis is focused on the analysis of data from Suzaku Key Project observations of the Perseus Cluster, the X-ray brightest cluster in the sky, which offered the most complete view to date of any galaxy cluster from its core to the outer edge. The results are presented across several chapters. In Chapter 2, we examine the behaviour of various physical properties of the intracluster medium (ICM), some of which, most prominently including the entropy, indicate a presence of density inhomogeneities at large radii (r> r500). In Chapter 3, we report evidence for large megaparsec-scale sloshing motions of the ICM in Perseus, a phenomenon which had not been observed before at these scales. In Chapter 4, we present the first spatially resolved study of the chemical composition of the ICM throughout the full volume of a cluster. Notably, we find a homogeneous distribution of heavy elements at large radii which indicates that these elements, produced by supernovae, were likely injected into and mixed with the intergalactic gas before galaxy clusters formed. In the second part of this thesis, I present a detailed spectral examination of Suzaku observations of the four X-ray brightest clusters, in order to search for the presence of a ~3.5 keV X-ray emission line. The presence of such a line has been claimed in some previous X-ray studies of the Perseus Cluster, and some other galaxies and clusters. It has been proposed that such a feature could be a decay signature from sterile neutrino dark matter. My results present a severe challenge to this interpretation. Alternative scenarios for the origin of the ~3.5 keV feature are discussed.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Urban, Ondrej |
|---|---|
| Associated with | Stanford University, Department of Physics. |
| Primary advisor | Allen, Steven |
| Thesis advisor | Allen, Steven |
| Thesis advisor | Madejski, Grzegorz |
| Thesis advisor | Wechsler, Risa H. (Risa Heyrman) |
| Advisor | Madejski, Grzegorz |
| Advisor | Wechsler, Risa H. (Risa Heyrman) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Ondrej Urban. |
|---|---|
| Note | Submitted to the Department of Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Ondrej Urban
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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