Institute of Astronomy

Dr Stephen Walker

E-mail: swalker@ast.cam.ac.uk

Personal Homepage

Office: Hoyle H54
Office Tel: (01223) 765848
More Info (Internal)

Preprints
Publications

Research

Galaxy clusters: cluster outskirts, AGN feedback, merging galaxy clusters, gas sloshing and cold fronts, sound waves and cavities in the ICM, cooling flows, filaments around galaxy cluster BCGs, constraints on turbulence in clusters, cluster merger shocks.

X-ray observations of hot haloes around massive spiral galaxies.

Selected papers

As first author:

[1]  Constraining gas motions in the Centaurus cluster using X-ray surface brightness fluctuations and metal diffusion

S. A. Walker, J. S. Sanders, A. C. Fabian, 2015, MNRAS accepted, (arXiv:1508.04285)

[2]  X-ray Analysis of Filaments in Galaxy Clusters

S. A. Walker, P. Kosec, A. C. Fabian, J. S. Sanders, 2015, MNRAS accepted, (arXiv:1508.01037)

[3]  A deep Chandra observation of the hot gaseous halo around a rare, extremely massive and relativistic jet launching spiral galaxy

S. A. Walker, J. Bagchi, A. C. Fabian, 2015, MNRAS, 449, 3527, (arXiv:1411.1930)

[4]  Exploring the origin of a large cavity in Abell 1795 using deep Chandra observations

S. A. Walker, A. C. Fabian, P. Kosec, 2014, MNRAS, 445, 3444, (arXiv:1409.6545)

[5]  The effect of the quasar H1821+643 on the surrounding intracluster medium: revealing the underlying cooling flow

S. A. Walker, A. C. Fabian, H. R. Russell, J. S. Sanders, 2014, MNRAS, 442, 2809 (arXiv:1405.7522)

[6]  Large scale gas sloshing out to half the virial radius in the strongest cool core REXCESS galaxy cluster, RXJ2014.8-2430

S. A. Walker, A. C. Fabian, J. S. Sanders, 2014, MNRAS, 441, L31, (arXiv:1402.6894)

[7]  An XMM-Newton view of the merging activity in the Centaurus cluster

S. A. Walker, A. C. Fabian, J. S. Sanders, 2013, MNRAS, 435, 3221, (arXiv:1308.2090)

[8]  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)

[9]  Galaxy cluster outskirts: a universal entropy profile for relaxed clusters?

S. A. Walker, A. C. Fabian, J. S. Sanders, M. R. George, 2012, MNRAS, 427, L45-L49 (arXiv:1208.5950)

[10]  Further X-ray observations of the galaxy cluster PKS 0745-191 to the virial radius and beyond 

S. A. Walker, A. C. Fabian, J. S. Sanders, M. R. George, 2012, MNRAS, 424, 1826 (arXiv:1205.2276)

[11]  X-ray observations of the galaxy cluster Abell 2029 to the virial radius

S. A. Walker, A. C. Fabian, J. S. Sanders, M. R. George, Y. Tawara, 2012, MNRAS, 422, 3503 (arXiv:1203.0486)

As second author:

[12] Effects of the variability of the nucleus of NGC1275 on X-ray observations of the surrounding intracluster medium

A.C. Fabian, S.A. Walker, C. Pinto, H.R. Russell, A.C. Edge, 2015, MNRAS, 451, 3061, (arXiv:1505.03754)

[13]  Do high redshift quasars have powerful jets?

A.C. Fabian, S.A. Walker, A. Celotti, G. Ghisellini, P. Mocz, K.M. Blundell, R.G. McMahon, 2014, MNRAS, 442, L81-L84 (arXiv:1404.7367)

[14]  X-ray mapping the outer regions of galaxy clusters at z= 0.23 and 0.45

Q. Daniel Wang and Stephen Walker, 2014, MNRAS, 439, 1796 (arXiv:1401.6205)

As co-author:

[15]  The X-ray spectrum of the cooling-flow quasar H1821+643 : A massive black hole feeding off the intracluster medium

Christopher S. Reynolds, Anne M. Lohfink, Arif Babul, Andrew C. Fabian, Julie Hlavacek-Larrondo, Helen R. Russell, Stephen A. Walker, ApJ Letters, 792, L41, (arXiv:1408.4803)

[16]  Feedback, scatter and structure in the core of the PKS 0745-191 galaxy cluster

J. S. Sanders, A. C. Fabian, J. Hlavacek-Larrondo, H. R. Russell, G. B. Taylor, F. Hofmann, G. Tremblay, S. A. Walker, 2014, MNRAS, 444, 1497, (arXiv:1407.8008)

[17]  The X-ray coronae of the two brightest galaxies in the Coma cluster

J. S. Sanders, A. C. Fabian, M. Sun, E. Churazov, A. Simionescu, S. A. Walker, N. Werner, 2014, MNRAS, 439, 1182 (arXiv:1401.3131)

[18]  Linear structures in the core of the Coma cluster

J. S. Sanders, A. C. Fabian, E. Churazov, A. A. Schekochihin, A. Simionescu, S. A. Walker, N. Werner, 2013, Science, Vol. 341 no. 6152 pp. 1365-1368 (arXiv:1309.4866)

[19]  Thermodynamics of the Coma Cluster Outskirts 

A. Simionescu, N. Werner, O. Urban, S. W. Allen, A. C. Fabian, A. Mantz, K. Matsushita, P. E. J. Nulsen, J. S. Sanders, T. Sasaki, T. Sato, Y. Takei, S. A. Walker, 2013, ApJ, 775, (arXiv:1302.4140)

 

Selected Presentations

SnowCluster 2015 - The Physics of Galaxy Clusters, talk: Exploring the outskirts of galaxy clusters

XMM-Newton 2012 Science Workshop: Galaxy Clusters as Giant Cosmic Laboratories (ESAC, Madrid, Spain 21st - 23rd May 2012) - Exploring the outskirts of the galaxy clusters Abell 2029 and PKS 0745-191 to the virial radius

Page last updated: 19 August 2015 at 13:03