dissertation

Constraining Dark Matter Through the Study of Merging Galaxy Clusters

Outline

Abstract

Acknowledgements

• Dave
• Members of dissertation committee
  • Tony
    • Guidance, support, letter of recommendation
  • Marusa
    • guidance, letters of recommendation
• James Jee
• Perry Gee
• Jack Hughes
• Dan Marrone
• Phil Marshall, Risa Wechsler
• Emily
  • Being my first mentee
• MCC
  • taking raw ideas and turning them into something great
  • note a few specific members and their contributions
• UC Davis cosmology group
  • Teachers
    • Chris F., Lori, Lloyd, Andy, Patricia Boeshaar
  • Students
    • Brian (especially), Dave, Nicholas, Marius, Greg, Andrew, Sam, Paul, Ami, Jim, Chris, Jacqueline, Karen, Ali (?)
• Funding agencies
  • Chandra, HST, UC Davis,
• Astronomy community as a whole, whose generally open practices made progress much easier, telescopes, conferences
• parent friends
• Mom (healthy sense of overconfidence), Jim, Father and Thomas
• Nanny
• Kerri (dedicate to her), Evry and Lander

Body

1. Introduction (about 4-10 pages) (Much of this can be transferred from my talk)
   1. Overview of Standard Model of Cosmology
      1. Briefly how do we know what we "know"
   2. Highlight Dark Matter
      1. Historical review
         1. Zwicky, Rubin, Clowe & Markevitch
         2. Why dark matter and not modified gravity (merging clusters)
      2. Generaly accepted properties
         1. Nearly collisionless
         2. Compare in relation to baryons (quantity, interaction, etc.)
   3. Motivation for studying SIDM
      1. Early motivation and work (missing satellite problem, Spergel & Steinheardt)
      2. Early constraints. SIDM ruled out? (Miralda-Escudé 2002, Yoshidal et al. 2000, Dave et al. 2001, Gnedin & Ostriker 2001, Randall et al 2008, Hennawi & Ostriker 2002)
      3. Recent motivation (Dwarf core problem, Too Big to Fail, Central densities of clusters, recent SIDM simulation)
         1. How SIDM may resolve these "problems"
         2. Narrow window of parameter space to probe (Rocha et al. 2013)
      4. Why merging clusters may be best probe
         1. Note degeneracy of baryon and SIDM physics in these motivating probes (motivate merging clusters)
   4. How merging clusters are probes of SIDM
      1. Simple picture of merging cluster (diagram)
      2. 4 ways of constraining SIDM with merging clusters
         1. Highlight the galaxy-dark matter offset method
            1. Highlight advantages over other SIDM probes (i.e. different baryon systematics, due to different scales)
            2. Note systematics involved in this measurement
   5. Note on other probes of SIDM (beyond scope of dissertation)
2. Musket Ball Cluster: Observed Properties
   1. Intro
   2. Photometry
   3. Spectroscopy
   4. Weak Lensing
   5. SZ
   6. X-ray analysis
   7. Radio analysis
3. Dynamics Properties of Merging Clusters
   • copy from dynamics paper
4. Musket Ball Cluster: Dark Matter Implications
   1. WL - Gas offset
      • copy from my letter
   2. WL - Galaxy offset
      1. Ways of measuring the offset and uncertainty
         1. Recursive Centroid based
         2. Galaxy Poisson sampling of parent WL distribution
         3. How to factor in phi (i.e. angle of offset w.r.t. merger axis)?
      2. Systematics
   3. Conflict with Bullet?
      1. Physics of the galaxy dark matter offset
      2. Comparison of the expected offsets for the Musket Ball Cluster and the Bullet Cluster
5. Proposed Method for Constraining SIDM (i.e. MCC Plan)
   1. Intro
   2. Ensemble approach
      1. Radio relic sample
   3. Beyond Markevitch & Randall
      1. Weaknesses of existing work
      2. Importance sampling
      3. Populating subhalo's with galaxies
   4. Hydrodynamics?
6. Radio relic preliminary results
   1. Preliminary spec-z picture of observed mergers
   2. Detailed dynamics picture of Toothbrush relic

Appendix

1. Publications and Talks