Open AccessRadio relics in a cosmological cluster merger simulation
Author(s) -
Hoeft Matthias,
Brüggen Marcus,
Yepes Gustavo
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07227.x
Subject(s) - physics , astrophysics , galaxy cluster , luminosity , radio galaxy , cluster (spacecraft) , galaxy , astronomy , relativistic particle , x shaped radio galaxy , plasma , shock wave , synchrotron , radio telescope , shock (circulatory) , electron , medicine , computer science , nuclear physics , thermodynamics , programming language , quantum mechanics
Motivated by the discovery of a number of radio relics we investigate the fate of fossil radio plasma during a merger of clusters of galaxies using cosmological smoothed‐particle hydrodynamics simulations. Radio relics are extended, steep‐spectrum radio sources that do not seem to be associated with a host galaxy. One scenario whereby these relics form has been proposed by Enßlin & Gobal‐Krishna and proceeds via the compression of fossil radio plasma during a merger between clusters. The ensuing compression of the plasma can lead to a substantial increase in synchrotron luminosity and this appears as a radio relic. Our simulations show that relics are most likely found at the periphery of the cluster at the positions of the outgoing merger shock waves. Relics are expected to be very rare in the centre of the cluster where the lifetime of relativistic electrons is short and shock waves are weaker than in the cooler, peripheral regions of the cluster. These predictions can soon be tested with upcoming low‐frequency radio telescopes.