Details

Autor(en) / Beteiligte

• Eckert, D.
• Jauzac, M.
• Vazza, F.
• Owers, M. S.
• Kneib, J.-P.
• Tchernin, C.
• Intema, H.
• Knowles, K.

Titel

A shock front at the radio relic of Abell 2744

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2016-09, Vol.461 (2), p.1302-1307

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Radio relics are Mpc-scale diffuse radio sources at the peripheries of galaxy clusters which are thought to trace outgoing merger shocks. We present XMM–Newton and Suzaku observations of the galaxy cluster Abell 2744 (z = 0.306), which reveal the presence of a shock front 1.5 Mpc east of the cluster core. The surface-brightness jump coincides with the position of a known radio relic. Although the surface-brightness jump indicates a weak shock with a Mach number $\mathcal {M}=1.7_{-0.3}^{+0.5}$ , the plasma in the post-shock region has been heated to a very high temperature (∼13 keV) by the passage of the shock wave. The low-acceleration efficiency expected from such a weak shock suggests that mildly relativistic electrons have been re-accelerated by the passage of the shock front.