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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

DARK MATTER SUBHALOS AND THE X-RAY MORPHOLOGY OF THE COMA CLUSTER

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Author(s):
Andrade-Santos, Felipe [1, 2] ; Nulsen, Paul E. J. [1] ; Kraft, Ralph P. [1] ; Forman, William R. [1] ; Jones, Christine [1] ; Churazov, Eugene [3] ; Vikhlinin, Alexey [1]
Total Authors: 7
Affiliation:
[1] Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 - USA
[2] Univ Sao Paulo, Dept Astron IAG, Sao Paulo - Brazil
[3] Max Planck Inst Astrophys, D-85741 Garching - Germany
Total Affiliations: 3
Document type: Journal article
Source: ASTROPHYSICAL JOURNAL; v. 766, n. 2 APR 1 2013.
Web of Science Citations: 14
Abstract

Structure formation models predict that clusters of galaxies contain numerous massive subhalos. The gravity of a subhalo in a cluster compresses the surrounding intracluster gas and enhances its X-ray emission. We present a simple model, which treats subhalos as slow moving and gasless, for computing this effect. Recent weak lensing measurements by Okabe et al. have determined masses of similar to 10(13) M-circle dot for three mass concentrations projected within 300 kpc of the center of the Coma Cluster, two of which are centered on the giant elliptical galaxies NGC 4889 and NGC 4874. Adopting a smooth spheroidal beta-model for the gas distribution in the unperturbed cluster, we model the effect of these subhalos on the X-ray morphology of the Coma Cluster, comparing our results to Chandra and XMM-Newton X-ray data. The agreement between the models and the X-ray morphology of the central Coma Cluster is striking. With subhalo parameters from the lensing measurements, the distances of the three subhalos from the Coma Cluster midplane along our line of sight are all tightly constrained. Using the model to fit the subhalo masses for NGC 4889 and NGC 4874 gives 9.1 x 10(12) M-circle dot and 7.6 x 10(12) M-circle dot, respectively, in good agreement with the lensing masses. These results lend strong support to the argument that NGC 4889 and NGC 4874 are each associated with a subhalo that resides near the center of the Coma Cluster. In addition to constraining the masses and 3-d location of subhalos, the X-ray data show promise as a means of probing the structure of central subhalos. (AU)

FAPESP's process: 08/05970-0 - Galaxy cluster collisions and their astrophysical consequences
Grantee:Felipe Andrade Santos
Support type: Scholarships in Brazil - Doctorate