Observations of Extended Radio Emission in Clusters

We review observations of extended regions of radio emission in clusters; these include diffuse emission in ‘relics’, and the large central regions commonly referred to as ‘halos’. The spectral observations, as well as Faraday rotation measurements of background and cluster radio sources, provide the main evidence for large-scale intracluster magnetic fields and significant densities of relativistic electrons. Implications from these observations on acceleration mechanisms of these electrons are reviewed, including turbulent and shock acceleration, and also the origin of some of the electrons in collisions of relativistic protons by ambient protons in the (thermal) gas. Improved knowledge of non-thermal phenomena in clusters requires more extensive and detailed radio measurements; we briefly review prospects for future observations.

[1]  C. Haslam,et al.  A High-Resolution Survey of the Coma Cluster of Galaxies at 408 Mc./s. , 1959, Nature.

[2]  F. A. Aharonian,et al.  The nonthermal energy content and gamma ray emission of starburst galaxies and clusters of galaxies , 1994 .

[3]  A Bayesian view on Faraday rotation maps - Seeing the magnetic power spectra in galaxy clusters , 2005, astro-ph/0501211.

[4]  L. Guzzo,et al.  The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy cluster survey. V. The cluster catalogue , 2004, astro-ph/0405546.

[5]  Sven Kohle,et al.  Cluster Radio Relics as a Tracer of Shock Waves of the Large-Scale Structure Formation , 1997 .

[6]  G. Gavazzi,et al.  Capturing a Star Formation Burst in Galaxies Infalling onto the Cluster A1367 , 2003 .

[7]  XMM-Newton study of the two-dimensional structure of the REFLEX-DXL galaxy clusters , 2005, astro-ph/0507452.

[8]  W. Domainko,et al.  Discovery of diffuse radio emission at the center of the most X-ray-luminous cluster RX J1347.5-1145 , 2007, 0706.3000.

[9]  Cluster mergers and non‐thermal phenomena: a statistical magneto‐turbulent model , 2005 .

[10]  G. Giovannini,et al.  Particle reacceleration in the Coma cluster: radio properties and hard X‐ray emission , 2000, astro-ph/0008518.

[11]  G. Giovannini,et al.  Merging processes in galaxy clusters , 2002 .

[12]  Benedetta Ciardi,et al.  The 21-cm emission from the reionization epoch: extended and point source foregrounds , 2004 .

[13]  K. Makishima,et al.  Hard X-Ray Properties of Groups of Galaxies as Observed with ASCA , 2006, astro-ph/0612753.

[14]  P. Gomez,et al.  Do Cooling Flows Survive Cluster Mergers? , 2002 .

[15]  S. Schindler.  Mergers of Galaxy Clusters in Numerical Simulations , 2002 .

[16]  Bonn,et al.  Systematic bias in interstellar magnetic field estimates , 2003, astro-ph/0307330.

[17]  A. C. Fabian,et al.  The Properties of the X-Ray Holes in the Intracluster Medium of the Perseus Cluster , 2002 .

[18]  S. Colafrancesco,et al.  Cooling flows or warming rays , 2003, astro-ph/0304444.

[19]  T. Ensslin,et al.  The magnetic power spectrum in Faraday rotation screens , 2003, astro-ph/0302426.

[20]  T. Ohashi,et al.  Nonthermal Phenomena in Clusters of Galaxies , 2001, astro-ph/0105265.

[21]  J. Macleod,et al.  A large-scale magnetic feature in the galaxy cluster A 2319 , 1986 .

[22]  J. Kaastra,et al.  Chandra Observation of Abell 2142: Survival of Dense Subcluster Cores in a Merger , 2000 .

[23]  F. Paerels,et al.  Future Instrumentation for the Study of the Warm-Hot Intergalactic Medium , 2008, 0801.1064.

[24]  Huub Röttgering,et al.  LOFAR, a new low frequency radio telescope , 2003 .

[25]  G. Giovannini,et al.  The radio galaxies and the magnetic field in Abell 119 , 1999, astro-ph/9902019.

[26]  G. Giovannini,et al.  The giant radio halo in Abell 2163 , 2001, astro-ph/0104451.

[27]  G. Brunetti,et al.  Statistics of giant radio haloes from electron reacceleration models , 2006, astro-ph/0604103.

[28]  A. Atoyan,et al.  Clusters of galaxies: magnetic fields and nonthermal emission , 1998, astro-ph/9812458.

[29]  Steve Rawlings,et al.  Science with the square kilometre array , 2004 .

[30]  G. Giovannini,et al.  The halo radio source Coma C and the origin of halo sources , 1993 .

[31]  G. Blumenthal,et al.  BREMSSTRAHLUNG, SYNCHROTRON RADIATION, AND COMPTON SCATTERING OF HIGH- ENERGY ELECTRONS TRAVERSING DILUTE GASES. , 1970 .

[32]  M. Markevitch,et al.  Physics of the Merging Clusters Cygnus A, A3667, and A2065 , 1998, astro-ph/9812005.

[33]  F. Durret,et al.  Giant Ringlike Radio Structures Around Galaxy Cluster Abell 3376 , 2006, Science.

[34]  L. Guzzo,et al.  The ROSAT-ESO Flux-limited X-Ray (REFLEX) Galaxy Cluster Survey. IV. The X-Ray Luminosity Function , 2002 .

[35]  E. Greisen,et al.  The NRAO VLA Sky Survey , 1996 .

[36]  Matt,et al.  Hard X-Ray Emission from the Galaxy Cluster A2256. , 2000, The Astrophysical journal.

[37]  Magnetic Fields in Cluster Cores: Faraday Rotation in A400 and A2634 , 2001, astro-ph/0109177.

[38]  Alexey Vikhlinin,et al.  Shocks and cold fronts in galaxy clusters , 2007, astro-ph/0701821.

[39]  Astrophysics,et al.  Cosmic rays, radio halos and nonthermal X-ray emission in clusters of galaxies , 1999, astro-ph/9905122.

[40]  The large-scale structure of the diffuse radio halo of the Coma cluster at 1.4 GHz , 1996, astro-ph/9609189.

[41]  D. Burstein,et al.  The Intragroup Medium in Poor Groups of Galaxies , 1996 .

[42]  C. Crawford,et al.  Fields and filaments in the core of the Centaurus cluster , 2007, 0708.3264.

[43]  S. Allen,et al.  Magnetic fields in the Centaurus cluster , 2001, astro-ph/0109337.

[44]  G. Giovannini,et al.  A2255: the First Detection of Filamentary Polarized Emission in a Radio Halo , 2004, astro-ph/0411720.

[45]  R. Perley,et al.  VLA observations of 3C 295 - A young radio galaxy? , 1991 .

[46]  N. Yamasaki,et al.  Temperature Map of the Perseus Cluster of Galaxies Observed with ASCA , 2001, astro-ph/0110146.

[47]  Malcolm S. Longair,et al.  High energy astrophysics: The contents of the Universe – the grand design , 1981 .

[48]  G. Giovannini,et al.  Deep images of cluster radio halos , 2003 .

[49]  L. Feretti.  Non-thermal emission from the intracluster medium , 2005 .

[50]  Revised equipartition and minimum energy formula for magnetic field strength estimates from radio synchrotron observations , 2005, astro-ph/0507367.

[51]  M. Willson.  Radio Observations of the Cluster of Galaxies in Coma Berenices— the 5C4 Survey , 1970 .

[52]  C. Sarazin,et al.  Radio Halo and Relic Candidates from the Westerbork Northern Sky Survey , 2000, astro-ph/0010251.

[53]  S. Gabici,et al.  Alfvénic reacceleration of relativistic particles in galaxy clusters: MHD waves, leptons and hadrons , 2003, astro-ph/0312482.

[54]  W. Jaffe.  Origin and transport of electrons in the halo radio source in the Coma cluster. , 1977 .

[55]  Regularity in the X-ray surface brightness profiles of galaxy clusters and the M-T relation , 1999, astro-ph/9901092.

[56]  S. Maurogordato,et al.  ATCA observations of the galaxy cluster Abell 3921. I. Radio emission from the central merging sub-clusters , 2006, astro-ph/0607111.

[57]  Richard A. Perley,et al.  Magnetic fields in the Hydra A cluster , 1993 .

[58]  The cluster relic source in A 521 , 2005, astro-ph/0510433.

[59]  V. Petrosian.  On the Nonthermal Emission and Acceleration of Electrons in Coma and Other Clusters of Galaxies , 2001, astro-ph/0101145.

[60]  S. Borgani,et al.  Scaling laws in X-ray galaxy clusters at redshift between 0.4 and 1.3 , 2004 .

[61]  C. Sarazin,et al.  Nonthermal Bremsstrahlung and Hard X-Ray Emission from Clusters of Galaxies , 1999, astro-ph/9911335.

[62]  W. I. Newman,et al.  Quantification of Uncertainty in the Measurement of Magnetic Fields in Clusters of Galaxies , 2002, astro-ph/0204451.

[63]  The temperature-mass relation in magnetized galaxy clusters , 2001, astro-ph/0101302.

[64]  C. Burigana,et al.  Diffuse radio emission from the intracluster medium , 2004 .

[65]  D. Fiume,et al.  Hard X-Ray Emission from the Galaxy Cluster A3667 , 2001, astro-ph/0105049.

[66]  U. Toronto,et al.  A New Radio-X-Ray Probe of Galaxy Cluster Magnetic Fields , 2000, astro-ph/0011281.

[67]  T. Ensslin,et al.  Constraining the population of cosmic ray protons in cooling flow clusters with γ-ray and radio observations: Are radio mini-halos of hadronic origin? , 2003, astro-ph/0306257.

[68]  B. Burn.  On the Depolarization of Discrete Radio Sources by Faraday Dispersion , 1965 .

[69]  A. Bykov,et al.  Nonthermal emission from clusters of galaxies , 2000 .

[70]  F. Durret,et al.  Cosmological Shock Waves , 2008, 0801.0995.

[71]  R. Hunstead,et al.  A Powerful Radio Halo in the Hottest Known Cluster of Galaxies 1E 0657–56 , 2000, astro-ph/0006072.

[72]  Evidence for shock acceleration and intergalactic magnetic fields in a large-scale filament of galaxies ZwCl 2341.1+0000 , 2002, astro-ph/0204389.

[73]  W. M. Goss,et al.  PKS B1400−33: An Unusual Radio Relic in a Poor Cluster , 2002, astro-ph/0212154.

[74]  S. Molendi,et al.  HARD X-RAY RADIATION IN THE COMA CLUSTER SPECTRUM , 1999 .

[75]  Magnetic fields in the 3C 129 cluster , 2001, astro-ph/0104223.

[76]  K. Dolag,et al.  Cosmic Rays and Radio Halos in Galaxy Clusters: New Constraints from Radio Observations , 2007, 0710.0801.

[77]  G. Giovannini,et al.  Halo and relic sources in clusters of galaxies , 2000 .

[78]  K. Dolag,et al.  Non-Thermal Processes in Cosmological Simulations , 2008, 0801.1048.

[79]  Measuring the cluster magnetic field power spectra from Faraday rotation maps of Abell 400, Abell 2634 and Hydra A , 2003, astro-ph/0309441.

[80]  D. Astronomia,et al.  Particle acceleration in cooling flow clusters of galaxies: The case of Abell 2626 , 2003, astro-ph/0311275.

[81]  Y. Rephaeli,et al.  Rossi X-Ray Timing Explorer Observations of A2256 , 2003 .

[82]  M. Murgia,et al.  Magnetic fields and Faraday rotation in clusters of galaxies , 2004 .

[83]  S. Schindler,et al.  Correlation of the magnetic field and the intra-cluster gas density in galaxy clusters , 2001, astro-ph/0108485.

[84]  T. Ensslin,et al.  Low-Frequency VLA Observations of Abell 754: Evidence for a Cluster Radio Halo and Possible Radio Relics , 2001, astro-ph/0103492.

[85]  U. Innsbruck,et al.  Mass distribution in the most X-ray-luminous galaxy cluster RX J1347.5-1145 studied with XMM-Newton , 2007, 0706.3001.

[86]  Self-similarity of clusters of galaxies and the $L_{\sf X}{-} T$ relation , 2001, astro-ph/0105463.

[87]  H. Böhringer,et al.  The radio and X-ray properties of Abell 2319 , 1997 .

[88]  G. B. Taylor,et al.  Cluster Magnetic Fields , 2002 .

[89]  R. Cameron,et al.  The intracluster magnetic field power spectrum in Abell 665 , 2007, 0709.2652.

[90]  S. Gabici,et al.  Gamma rays from clusters of galaxies , 2007, astro-ph/0701545.

[91]  R. Ekers,et al.  THE EXTENDED RADIO EMISSION IN THE LUMINOUS X-RAY CLUSTER A3667 , 1997 .

[92]  G. Brunetti,et al.  Modeling the interaction between ICM and relativistic plasma in cooling flows: The case of the Perseus cluster , 2002, astro-ph/0202279.

[93]  Y. Rephaeli.  Relativistic electrons in the intracluster space of clusters of galaxies - The hard X-ray spectra and heating of the gas , 1979 .

[94]  A. Bykov,et al.  Nonthermal Radiation Mechanisms , 2008, 0801.1016.

[95]  Y. Rephaeli,et al.  Rossi X-Ray Timing Explorer Observations of the Coma Cluster , 1999 .

[96]  L. G. Sijbring.  A radio continuum and H1 line study of the Perseus Cluster , 1993 .

[97]  S. Okamura,et al.  A Comparison of the Galaxy Populations in the Coma and Distant Clusters: The Evolution of k+a Galaxies and the Role of the Intracluster Medium , 2003, astro-ph/0309449.

[98]  J. Kempner,et al.  A Chandra view of the multiple merger in Abell 2744 , 2003, astro-ph/0310185.

[99]  C. Benoist,et al.  Dynamical state and star formation properties of the merging galaxy cluster Abell 3921 , 2004, astro-ph/0409072.

[100]  H. Andernach,et al.  Four Extreme Relic Radio Sources in Clusters of Galaxies , 2001, astro-ph/0105267.

[101]  G. Swarup,et al.  The universe at low radio frequencies : proceedings of the 199th symposium of the International Astronomical Union held in Pune, India, 30 Novenber-4 December 1999 , 2002 .

[102]  G. Pratt,et al.  The late merging phase of a galaxy cluster : XMM EPIC observations of A 3266 , 2005, astro-ph/0508682.

[103]  K. Institute,et al.  Faraday rotation measure synthesis , 2005, astro-ph/0507349.

[104]  Optical Analysis of Cluster Mergers , 2002 .

[105]  Germany,et al.  The structural and scaling properties of nearby galaxy clusters. II. The M-T relation , 2005, astro-ph/0502210.

[106]  Radio halo and relic candidates from the NRAO VLA Sky Survey , 1999, astro-ph/9904210.

[107]  M. Longair,et al.  The synchrotron spectra of radio hot spots. , 1989 .

[108]  K. Dolag,et al.  New scaling relations in cluster radio haloes and the re‐acceleration model , 2007, 0704.3490.

[109]  V. Vacca,et al.  The intracluster magnetic field power spectrum in Abell 2255 , 2006, astro-ph/0608433.

[110]  Low frequency study of two clusters of galaxies: A2744 and A2219 , 2007, astro-ph/0701776.

[111]  Torsten A. Ensslin,et al.  The radio luminosity function of cluster radio halos , 2002, astro-ph/0209218.

[112]  Long RXTE Observations of A2163 , 2006, astro-ph/0606097.

[113]  P. Dewdney,et al.  The halo and magnetic field of the Coma cluster of galaxies , 1990 .

[114]  Multiple merging events in Abell 521 , 2002, astro-ph/0211592.

[115]  A. Konovalenko,et al.  The Universe at Very Low Radio Frequencies , 2002 .

[116]  P. Blasi.  Stochastic Acceleration and Nonthermal Radiation in Clusters of Galaxies , 2000, The Astrophysical journal.

[117]  K.-T. Kim,et al.  Detection of excess rotation measure due to intracluster magnetic fields in clusters of galaxies , 1991 .

[118]  P. Blasi,et al.  Clusters of Galaxies as Storage Room for Cosmic Rays , 1996, astro-ph/9609048.

[119]  M. Markevitch,et al.  SUBMITTED TO APJ Preprint typeset using L ATEX style emulateapj v. 04/03/99 MERGER SHOCKS IN GALAXY CLUSTERS A665 AND A2163 AND THEIR RELATION TO RADIO HALOS , 2001 .

[120]  S. Allen,et al.  Chandra measurements of the distribution of mass in the luminous lensing cluster Abell 2390 , 2000, astro-ph/0008517.

[121]  D. Buote.  On the Origin of Radio Halos in Galaxy Clusters , 2001, astro-ph/0104211.

[122]  Torsten A. Ensslin Gopal-Krishna.  Reviving fossil radio plasma in clusters of galaxies by adiabatic compression in environmental shock waves , 2000, astro-ph/0011123.

[123]  Tracy E. Clarke,et al.  Deep 1.4 GHz Very Large Array Observations of the Radio Halo and Relic in Abell 2256 , 2006, astro-ph/0603166.

[124]  A. Evrard,et al.  Clusters, Cosmology and Mergers , 2002 .

[125]  Y. Rephaeli.  Spatial distribution of compton-produced X-ray flux from rich and regular clusters of galaxies , 1977 .

[126]  M. Markevitch,et al.  Chandra Estimate of the Magnetic Field Strength near the Cold Front in A3667 , 2000, astro-ph/0008499.

[127]  Moscow,et al.  Bow Shock and Radio Halo in the Merging Cluster A520 , 2004, astro-ph/0412451.

[128]  C. Jones,et al.  Einstein Observatory Images of Clusters of Galaxies , 1999 .

[129]  G. Gisler,et al.  Where have all the cluster halos gone , 1992 .

[130]  T. Clarke.  Faraday rotation observations of magnetic fields in galaxy clusters , 2004, astro-ph/0412268.

[131]  Usa,et al.  Spectral index maps of the radio halos in Abell 665 and Abell 2163 , 2004, astro-ph/0404283.

[132]  Luigina Feretti,et al.  Diffuse thermal and relativistic plasma in galaxy clusters : proceedings of the workshop held at Ringberg Castle, Germany, April 19 - 23, 1999 , 1999 .

[133]  A comparison of radio and X-ray morphologies of four clusters of galaxies containing radio halos , 2001, astro-ph/0101418.

[134]  U. Klein,et al.  The diffuse radio emission from the Coma cluster at 2.675 GHz and 4.85 GHz , 2003 .

[135]  S. Ettori,et al.  Chandra imaging of the complex X-ray core of the Perseus cluster , 2000, astro-ph/0007456.

[136]  M. Murgia,et al.  Radio and X-ray diffuse emission in six clusters of galaxies , 2001 .

[137]  Y. Rephaeli,et al.  Turbulent Generation of Intracluster Magnetic Fields and Faraday Rotation Measurements , 1993 .

[138]  F. Govoni,et al.  In search of dying radio sources in the local universe , 2007, 0705.3209.

[139]  T. Ensslin,et al.  Are the Faraday Rotating Magnetic Fields Local to Intracluster Radio Galaxies? , 2003, astro-ph/0301552.

[140]  B. Dennison,et al.  Formation of radio halos in clusters of galaxies from cosmic-ray protons , 1980 .

[141]  Cosmic Ray Acceleration during Large Scale Structure Formation , 2004, astro-ph/0412572.

[142]  G. Giovannini,et al.  Diffuse Radio Sources and Cluster Mergers , 2002 .

[143]  Luigina Feretti,et al.  Radio Galaxies and Their Environment , 2002 .

[144]  B. Dennison,et al.  On intracluster Faraday rotation. II - Statistical analysis , 1982 .

[145]  Radio signature of cosmological structure formation shocks , 2006, astro-ph/0609831.

[146]  S. Baum,et al.  Multifrequency VLA observations of PKS 0745 - 191 - The archetypal 'cooling flow' radio source? , 1991 .

[147]  Spectral properties and origin of the radio halo in A3562 , 2005, astro-ph/0505614.

[148]  F. Miniati.  Numerical modelling of gamma radiation from galaxy clusters , 2003, astro-ph/0303593.

[149]  UK.,et al.  Simulations of galactic winds and starbursts in galaxy clusters , 2005, astro-ph/0508107.