Alfvénic reacceleration of relativistic particles in galaxy clusters: MHD waves, leptons and hadrons

By Gianfranco Brunetti, P. Blasi, R. Cassano, S. Gabici. 2003

134 citations recorded by the source corpus.

There is growing evidence that extended radio haloes are most likely generated by electrons reaccelerated via some kind of turbulence generated in the cluster volume during major mergers. It is well known that Alfven waves channel most of their energy flux in the acceleration of relativistic particles. Much work has been done recently to study this phenomenon and its consequences for the explanation of the observed non-thermal phenomena in clusters of galaxies. We investigate here the problem of particle-wave interactions in the most general situation in which relativistic electrons, thermal protons and relativistic protons exist within the cluster volume. The interaction of all these components with the waves, as well as the turbulent cascading and damping processes of Alfven waves, are treated in a fully time-dependent way. This allows us to calculate the spectra of electrons, protons and waves at any fixed time. The Lighthill mechanism is invoked to couple the fluid turbulence, supposedly injected during cluster mergers, to MHD turbulence. We find that present observations of non-thermal radiation from clusters of galaxies are well described within this approach, provided the fraction of relativistic hadrons in the intracluster medium (ICM) is smaller than 5-10 per cent.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/7ca3bc5a25bb5ad7239cd0eb5c5735064da5ee34

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

Compressible turbulence in galaxy clusters: physics and stochastic particle re-acceleration (2007, background): “…acceleration of particles in many astrophysical environments, e.g. Solar wind, Solar flares, ICM, gamma-ray bursts (see Schlickeiser & Miller 1998; Chandran 2003; Brunetti et al. 2004; Petrosian & Liu 2004; Cho & Lazarian 2006; Petrosian et al. 2006; Becker, Le & Dermer 2006; Dogiel et al. 2007).”
Cluster Mergers and Non-Thermal Phenomena: A Statistical Magneto-Turbulent Model (2004, background): “More recently, Brunetti et al. (2004) presented the first self-consistent and time-dependent model for the interaction of Alfvén waves, relativistic electrons, thermal and relativistic protons in galaxy clusters.”
SEARCH FOR COSMIC-RAY-INDUCED GAMMA-RAY EMISSION IN GALAXY CLUSTERS (2013, background): “…through the second order Fermi process to sufficiently high energies to explain the observed radio emission (Schlickeiser et al. 1987; Brunetti et al. 2001; Petrosian 2001; Brunetti et al. 2004; Brunetti & Blasi 2005; Brunetti & Lazarian 2007, 2011; Brunetti et al. 2009; Donnert et al. 2013).”
Detecting shock waves in cosmological smoothed particle hydrodynamics simulations (2006, background): “…can accumulate within the ICM (Sarazin 2002), until they experience continuous in-situ acceleration either via shock acceleration or resonant pitch angle scattering on turbulent Alfvén waves (Jaffe 1977; Schlickeiser et al. 1987; Brunetti et al. 2001; Ohno et al. 2002; Brunetti et al. 2004).”
Multi-frequency analysis of neutralino dark matter annihilations in the Coma cluster (2005, background): “…for the radio-halo emission features of Coma has been interpreted as synchrotron emission from a population of primary relativistic electrons which are subject to a continuous re-acceleration process supposedly triggered by merging shock and/or intracluster turbulence (e.g., Brunetti et al. 2004).”
Shock waves in Eulerian cosmological simulations: main properties and acceleration of cosmic rays (2008, background): “Large-scale radio emission in the form of giant radio haloes may be powered by particle re-acceleration by magnetohydrodynamics (MHD) turbulence injected in the ICM during energetic merging events (Brunetti et al. 2001, 2004, 2008; Petrosian 2001).”
Feedback heating by cosmic rays in clusters of galaxies (2007, background): “The significance of the resonant interaction of cosmic rays with hydromagnetic waves has been recognized and discussed by many authors in various astrophysical contexts (e.g., Melrose (1968); Skilling (1971); Blandford & Ostriker (1978); Loewenstein et al. (1991); Brunetti et al. (2004)).”
Cosmic ray transport in galaxy clusters: implications for radio halos, gamma-ray signatures, and cool core heating (2010, background): “This leads to a larger macroscopic displacement from the original magnetic field line when the particles follow the 2 Schlickeiser et al. (1987); Giovannini et al. (1993); Brunetti et al. (2004); Brunetti & Blasi (2005); Brunetti & Lazarian (2007, 2011); Brunetti et al. (2009).”
Evolving turbulence and magnetic fields in galaxy clusters (2005, background): “The turbulent flow of magnetized gas can accelerate relativistic particles required to produce cluster radio haloes (Tribble 1993b; Brunetti et al. 2004; Cassano & Brunetti 2005).”
Acceleration of primary and secondary particles in galaxy clusters by compressible MHD turbulence: from radio haloes to gamma-rays (2010, background): “…of fact, assuming that primary electrons are dominant with respect to secondaries our picture evolves into the ”classical” reacceleration model (eg., Brunetti et al 2001, 2004; Petrosian 2001; Cassano & Brunetti 2005) where indeed the luminosity of giant radio halos is suppressed by several…”
Simulating cosmic rays in clusters of galaxies – II. A unified scheme for radio haloes and relics with predictions of the γ-ray emission (2007, background): “…within the ICM (Sarazin2002), until they experience continuous in-situ acceleration either via interactions with magneto-hydrodynamic waves, or through turbulent spectra (Jaffe 1977; Schlickeiser et al. 1987; Brunetti et al. 2001; Ohno et al. 2002; Brunetti et al. 2004; Brunetti & Lazarian 2007).”
Turbulent gas motions in galaxy cluster simulations: the role of smoothed particle hydrodynamics viscosity (2005, unknown): “A number of approaches for studying the acceleration of relativistic electrons in the ICM have been successfully developed by focusing on the case of Alfvén waves (Ohno et al. 2002; Brunetti et al. 2004) and, more recently, on Fast Mode-waves (Cassano & Brunetti 2005).”