Stephen Walker, Ph.D.

Associate Professor, Physics and Astronomy

Contact

301 Sparkman Drive
Optics Building
Room 216
Huntsville, AL 35899
Campus Map

256.824.2593
stephen.walker@uah.edu

Biography

I started at UAH as an Assistant Professor in 2019. Prior to this I have been a NASA Postdoctoral Program (NPP) Fellow at NASA’s Goddard Space Flight Center, and a postdoctoral researcher at the University of Cambridge.

My research concentrates on all aspects of galaxy clusters (the largest collapsed structures in the universe), from the outskirts where they are continuing to form from the cosmic web, to gas sloshing produced by galaxy cluster mergers, to studying AGN feedback in cluster cores, focusing on their X-ray emission.

Curriculum Vitae

Personal Website

Education

  • Ph.D., University of Cambridge, 2014
  • Master of Physics, University of Oxford, 2010

Research Funding

  • 2020-2023: “Deep Chandra observations of the strong shock in the merging cluster SPT-CLJ2031-4037”, PI: S. A. Walker, $80k, Smithsonian Astrophysical Observatory
  • 2020-2023: “A high resolution view of the extreme 1Mpc radius cold front in A2142”, PI: S. A. Walker, $70k, Smithsonian Astrophysical Observatory
  • 2019-2022: “A complete view of the colossal 700kpc radius cold front in the Perseus cluster”, PI: S. A. Walker, $99k, Smithsonian Astrophysical Observatory
  • 2020-2023: “A detailed view of the group NGC 4839 as it merges with the Coma cluster”, PI: S. A. Walker, $91k, Smithsonian Astrophysical Observatory
  • 2019-2022: “Is there an enormous cold front at the virial radius of the Perseus cluster?”, PI: S. A. Walker, $93k, Smithsonian Astrophysical Observatory
  • 2019-2022: “Probing within the Bondi radius of the ultramassive black hole in NGC 1600”, PI: S. A. Walker, $82k, Smithsonian Astrophysical Observatory
  • 2020-2021: “A complete view of the sloshing activity in the Perseus cluster”. PI: S. A. Walker, $78k, NASA
  • 2020-2021: “The clearest view of the outskirts of a galaxy cluster: the Coma cluster”, PI: S. A. Walker, $108k, NASA
  • 2019-2020: “Is there an enormous cold front at the virial radius of the Perseus cluster?”, PI: S. A. Walker, $70k, NASA

Expertise

  • Galaxy Clusters
  • Active Galactic Nuclei
  • Cosmology

Recent Publications

  • The Physics of Galaxy Cluster Outskirts. Stephen Walker, Aurora Simionescu, Daisuke Nagai, Nobuhiro Okabe, Dominique Eckert, Tony Mroczkowski, Hiroki Akamatsu, Stefano Ettori, Vittorio Ghirardini, 2019, Space Science Reviews, 215: 7, doi.org/10.1007/s11214-018-0572-8 (arXiv:1810.00890)

  • The split in the ancient cold front in the Perseus cluster. Stephen A. Walker, John ZuHone, Andy Fabian, Jeremy Sanders, 2018, Nature Astronomy 2, 292-296, (arXiv:1803.00898)

  • Is there a giant Kelvin-Helmholtz instability in the sloshing cold front of the Perseus cluster? S. A. Walker, J. Hlavacek-Larrondo, M. Gendron-Marsolais, A. C. Fabian, H. Intema, J. S. Sanders, J. T. Bamford, R. van Weeren, 2017, MNRAS, 468, 2506, (arXiv:1705.00011)

  • X-ray exploration of the outskirts of the nearby Centaurus cluster using Suzaku and Chandra. S. A. Walker, A. C. Fabian, J. S. Sanders, A. Simionescu, Y. Tawara, 2013, MNRAS, 432, 554, (arXiv:1303.4240)