LOFAR observations of SZ-selected galaxy clusters, and high-fidelity imaging

• Applicants: Professor Marcus Brüggen, Ph.D.; Professor Dr. Ulrich Klein
• Subject Area: Astrophysics and Astronomy
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 108727618

• Final Report Year: 2017

Final Report Abstract

We have investigated the radio continuum properties of radio halos and relics in galaxy clusters over large frequency range. In particular, low-frequency observations of such structures which usually exhibit steep spectra were conducted using LOFAR and the GMRT. The number of galaxy clusters with known radio haloes and/or relics has been significantly increased by our studies, making use of both, X-ray and Sunyaev-Zel’dovich observations that have dramatically increased the number of known distant galaxy clusters. Furthermore, some well-known relics in nearby galaxy clusters have been subject to scrutiny, comparing their radio and X-ray properties. Assuming that diffusive shock acceleration is the underlying mechanism producing highly relativistic particles, the Mach numbers resulting from the observed radio spectral index were compared with those deduced from jumps in the gas density in several nearby clusters. In some cases, the contradicting results highlight the need for additional theoretical work and numerical simulations of particle acceleration and re-acceleration at cluster merger shocks.

Publications

• 2014, MNRAS, 426, 40
  Bonafede, A., Brüggen, M., van Weeren, R. Vazza, F., Giovannini, G., Ebeling, H., Edge, A.C., Hoeft, M., Klein, U.
  
• 2014, A&A, 543, 43
  van Weeren, R.J., Intema, H.T., Lal, D.V.., Röttgering, H.J.A., Brüggen, M., Stroe, A., Hoeft, M., Nuza, S.E., de Gasperin, F.
  
• 2014, MNRAS, 444, 44
  Bonafede, A., Intema, H., Brüggen, M. et al.
  
• 2015, A&A, 575, 45
  Trasatti, M., Akamatsu, H., Lovisari, L., Klein, U., Bonafede, A., Brüggen, M., Dallacasa, D., Clarke, T.
  
• 2015, A&A, 575, 8
  Drabent, A., Hoeft, M., Pizzo, R.F., van Weeren, R., Klein, U.
  
• 2015, ApJ, 785, 1
  Bonafede, A., Intema, H., Brüggen, M., Girardi, M. et al.
  
• 2015, MNRAS, 447, 2497
  Erler, J., Basu, K., Trasatti, M., Klein, U., Bertoldi, F.
  
• 2015, MNRAS, 454, 3391
  Bonafede, A., Intema, H., Brüggen, M., Vazza, F. et al.
  
• 2016, MNRAS, 461, 1302
  Eckert, D., Jauzac, M., Vazza, F. et al.
  
• 2017, A&A, 600, 18
  Kierdorf, M., Beck, R., Hoeft, M., Klein, U. et al.