Frontier fields clusters: deep Chandra observations of the complex merger MACS~J1149.6+2223

Ogrean, G. A.; Van Weeren, R. J.; Jones, C.; Forman, W.; Dawson, W. A.; Golovich, N.; Andrade-Santos, F.; Murray, S. S.; Nulsen, P.; Roediger, E.; Zitrin, A.; Bulbul, E.; Kraft, R.; Goulding, A.; Umetsu, K.; Mroczkowski, T.; Bonafede, A.; Randall, S.; Sayers, J.; Churazov, E.; David, L.; Merten, J.; Donahue, M.; Mason, B.; Rosati, P.; Vikhlinin, A.; Ebeling, H.

Abstract

The Hubble Space Telescope Frontier Fields cluster MACS J1149.6+2223 is one of the most complex merging clusters, believed to consist of four dark matter halos. We present results from deep (365 ks) Chandra observations of the cluster, which reveal the most distant cold front (z = 0.544) discovered to date. In the cluster outskirts, we also detect hints of a surface brightness edge that could be the bow shock preceding the cold front. The substructure analysis of the cluster identified several components with large relative radial velocities, thus indicating that at least some collisions occur almost along the line of sight. The inclination of the mergers with respect to the plane of the sky poses significant observational challenges at X-ray wavelengths. MACS J1149.6+2223 possibly hosts a steep-spectrum radio halo. If the steepness of the radio halo is confirmed, then the radio spectrum, combined with the relatively regular ICM morphology, could indicate that MACS J1149.6+2223 is an old merging cluster.

Citation

Ogrean, G. A., Van Weeren, R. J., Jones, C., Forman, W., Dawson, W. A., Golovich, N., Andrade-Santos, F., Murray, S. S., Nulsen, P., Roediger, E., Zitrin, A., Bulbul, E., Kraft, R., Goulding, A., Umetsu, K., Mroczkowski, T., Bonafede, A., Randall, S., Sayers, J., Churazov, E., …Ebeling, H. (2016). Frontier fields clusters: deep Chandra observations of the complex merger MACS~J1149.6+2223. The Astrophysical journal, 819(2), 113-1-113-13. https://doi.org/10.3847/0004-637X/819/2/113

• Journal Article Type: Article
• Acceptance Date: Nov 25, 2015
• Online Publication Date: Mar 4, 2016
• Publication Date: Mar 10, 2016
• Deposit Date: Mar 17, 2016
• Publicly Available Date: Mar 17, 2016
• Journal: The astrophysical journal
• Print ISSN: 0004-637X
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 819
• Issue: 2
• Pages: 113-1-113-13
• DOI: https://doi.org/10.3847/0004-637X/819/2/113
• Keywords: Galaxies : clusters : general, Galaxies : clusters : individual : MACS J1149.6+2223, Galaxies : clusters : intracluster medium
• Public URL: https://hull-repository.worktribe.com/output/433752
• Publisher URL: http://iopscience.iop.org/article/10.3847/0004-637X/819/2/113/meta;jsessionid=3A36E409526442B83209A67DB83CCBA2.c4.iopscience.cld.iop.org
• Additional Information: This is a copy of an article published in the astrophysical journal, 2016, v.819 issue 2.
• Contract Date: Mar 17, 2016