The "Sausage" and "Toothbrush" clusters of galaxies and the prospects of LOFAR observations of clusters of galaxies
Artikel i vetenskaplig tidskrift, 2013

LOFAR, the Low Frequency Radio Array, is a new pan-European radio telescope that is almost fully operational. One of its main drivers is to make deep images of the low frequency radio sky. To be able to do this a number of challenges need to be addressed. These include the high data rates, removal of radio frequency interference, calibration of the beams and correcting for the corrupting influence of the ionosphere. One of the key science goals is to study merger shocks, particle acceleration mechanisms and the structure of magnetic fields in nearby and distant merging clusters. Recent studies with the GMRT and WSRT radio telescopes of the "Sausage" and the "Toothbrush" clusters have given a very good demonstration of the power of radio observations to study merging clusters. Recently we discovered that both clusters contain relic and halo sources, large diffuse regions of radio emission not associated with individual galaxies. The 2 Mpc northern relic in the Sausage cluster displays highly aligned magnetic fields and and exhibits a strong spectral index gradient that is a consequence of cooling of the synchrotron emitting particles in the post-shock region. We have argued that these observations provide strong evidence that shocks in merging clusters are capable of accelerating particles. For the Toothbrush cluster we observe a puzzling linear relic that extends over 2 Mpc. The proposed scenario is that a triple-merger can lead to such a structure. With LOFAR's sensitivity it will not only be possible to trace much weaker shocks, but also to study those shocks due to merging clusters up to redshifts of at least one. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

galaxies: clusters: general

1RXS J0603.3+4214)

galaxies: clusters: individual(CIZA

calibration

telescopes

J2242.8+5301

ciza j2242.8+5301

mergers

Författare

H. Rottgering

Leiden University

R. van Weeren

Smithsonian Astrophysical Observatory

M. Brüggen

Universität Hamburg

J. Croston

University of Southampton

M. Hoeft

Thüringer Landessternwarte Tautenburg

G. Ogrean

Universität Hamburg

P. D. Barthel

University of Groningen, Kapteyn Astronomical Institute

P. Best

Royal Observatory

A. Bonafede

Universität Hamburg

G. Brunetti

INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna

R. Cassano

INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna

K. Chyzy

Uniwersytet Jagiellonski w Krakowie

John Conway

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

F. De Gasperin

Universität Hamburg

C. Ferrari

Universite Nice Sophia Antipolis

G. Heald

Netherlands Institute for Radio Astronomy (ASTRON)

N. Jackson

University of Manchester

M.J. Jarvis

University of Oxford

University of the Western Cape

M. Lehnert

GEPI - Galaxies, Etoiles, Physique, Instrumentation

G. Macario

Universite Nice Sophia Antipolis

G. Miley

Leiden University

E. Orru

Netherlands Institute for Radio Astronomy (ASTRON)

R. Pizzo

Netherlands Institute for Radio Astronomy (ASTRON)

D. Rafferty

Leiden University

A. Stroe

Leiden University

C. Tasse

Rhodes University

S. van der Tol

Leiden University

G. White

Open University

Rutherford Appleton Laboratory

M. Wise

Netherlands Institute for Radio Astronomy (ASTRON)

Astronomische Nachrichten

0004-6337 (ISSN) 1521-3994 (eISSN)

Vol. 334 333-337

Ämneskategorier

Astronomi, astrofysik och kosmologi

DOI

10.1002/asna.201211847