Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-02-10
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
13 pages, 18 figures, accepted for publication in A&A on January 11, 2011
Scientific paper
Some merging galaxy clusters host diffuse elongated radio sources, also called radio relics. It is proposed that these radio relics trace shock waves in the intracluster medium created during a cluster merger event. Within the shock waves particles are accelerated to relativistic energies, and in the presence of a magnetic field synchrotron radiation will be emitted. Here we present GMRT and WSRT observations of a new double relic in the galaxy cluster ZwCl 0008.8+5215. Optical V, R, and I band images of the cluster were taken with the INT. An optical spectrum, to determine the redshift of the cluster, was taken with the WHT. Our observations show the presence of a double radio relic in the galaxy cluster ZwCl 0008.8+5215, for which we find a spectroscopic redshift of z = 0.1032 \pm 0.0018 from an optical spectrum of one of the cD galaxies. The spectral index of the two relics steepens inwards to the cluster center. For part of the relics, we measure a polarization fraction in the range ~ 5-25%. A ROSAT X-ray image displays an elongated ICM and the large-scale distribution of galaxies reveals two cluster cores, all pointing towards a binary cluster merger event. The radio relics are located symmetrically with respect to the X-ray center of the cluster, along the proposed merger axis. The relics have a linear extent of 1.4 Mpc and 290 kpc. This factor of five difference in linear size is unlike that of previously known double relic systems, for which the sizes do not differ by more than a factor of two. We conclude that the double relics in ZwCl 0008.8+5215 are best explained by two outward moving shock waves in which particles are (re)accelerated trough the diffusive shock acceleration (DSA) mechanism. [abridged]
Brüggen Marcus
Hoeft Matthias
Intema Hubertus Theodorus
R"ottgering Huub J. A.
van Weeren Reinout Johannes
No associations
LandOfFree
A double radio relic in the merging galaxy cluster ZwCl 0008.8+5215 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A double radio relic in the merging galaxy cluster ZwCl 0008.8+5215, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A double radio relic in the merging galaxy cluster ZwCl 0008.8+5215 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-631548