docA Pedagogical Guide to Radio Phenomenon in Clusters
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A Pedagogical Guide to Radio Phenomenon in Clusters
Radio phenomenology Cosmic ray transport A Pedagogical Guide to Radio Phenomenon in Clusters Christoph Pfrommer1 in collaboration with Nick Battaglia, Dick Bond, Torsten Enßlin, Francesco Miniati, Anders Pinzke, John Sievers, Kandaswamy Subramanian 1 Heidelberg Institute for Theoretical Studies, Germany Kavli Institute for Theoretical Physics, Santa Barbara Apr 21, 2011 / KITP program Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Outline 1 Radio phenomenology Overview Observations Radio gischt emission 2 Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Outline 1 Radio phenomenology Overview Observations Radio gischt emission 2 Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Hadronic cosmic ray proton interaction e+ µ+ π+ CRp π 0 νµ _ νe νµ p Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Hadronic cosmic ray proton interaction e+ magnetic field µ+ π+ CRp π p γ νµ 0 _ νe νµ radio + IC γ Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Multi messenger approach for non-thermal processes Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Multi messenger approach for non-thermal processes Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Multi messenger approach for non-thermal processes Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Multi messenger approach for non-thermal processes Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission What we hope to learn from non-thermal emission plasma astrophysics: shock and particle acceleration large-scale magnetic fields turbulence dynamical state → cosmology? non-thermal pressure support: hydrostatics + SZE history of individual clusters: cluster archeology illuminating the process of structure formation consistent picture of non-thermal processes: radio, soft/hard X-rays, γ-rays Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Overview of diffuse radio phenomenon radio relics: αν ∼ 1 − 2.5, where jν ∝ ν −αν radio relic bubble: aged radio cocoon, steep spectrum radio phoenix: shock-revived bubble that has already faded out of the radio window → adiabatic compression? radio gischt: irregular morphology, at cluster periphery (< Mpc), in some cases coincident with weak X-ray shock, polarized → diffusive shock acceleration (Fermi I)? radio halos: centrally located, regular morphology, αν ∼ 1 − 1.5, unpolarized → volume filling radio emission giant radio halos: occur in merging clusters, > 1 Mpc-sized, morphology similar to X-rays radio mini halos: occur in cool core clusters, few times 100 kpc in size, emission extends over cool core Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Overview of diffuse radio phenomenon radio relics: αν ∼ 1 − 2.5, where jν ∝ ν −αν radio relic bubble: aged radio cocoon, steep spectrum radio phoenix: shock-revived bubble that has already faded out of the radio window → adiabatic compression? radio gischt: irregular morphology, at cluster periphery (< Mpc), in some cases coincident with weak X-ray shock, polarized → diffusive shock acceleration (Fermi I)? radio halos: centrally located, regular morphology, αν ∼ 1 − 1.5, unpolarized → volume filling radio emission giant radio halos: occur in merging clusters, > 1 Mpc-sized, morphology similar to X-rays radio mini halos: occur in cool core clusters, few times 100 kpc in size, emission extends over cool core Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Radio phoenix thermal X-ray emission Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Shock overruns an aged radio bubble (C.P. & Jones 2011) Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Bubble transformation to vortex ring Enßlin & Brüggen (2002): gas density (top) and magnetic energy density (bottom) Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Radio gischt: double relic sources CIZA J2242.8+5301 (“sausage relic”) Abell 3667 (X-ray: XMM; radio: WSRT; Ogrean+ in prep.) (radio: Johnston-Hollitt. X-ray: ROSAT/PSPC.) Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Overview of diffuse radio phenomenon radio relics: αν ∼ 1 − 2.5, where jν ∝ ν −αν radio relic bubble: aged radio cocoon, steep spectrum radio phoenix: shock-revived bubble that has already faded out of the radio window → adiabatic compression? radio gischt: irregular morphology, at cluster periphery (< Mpc), in some cases coincident with weak X-ray shock, polarized → diffusive shock acceleration (Fermi I)? radio halos: centrally located, regular morphology, αν ∼ 1 − 1.5, unpolarized → volume filling radio emission giant radio halos: occur in merging clusters, > 1 Mpc-sized, morphology similar to X-rays radio mini halos: occur in cool core clusters, few times 100 kpc in size, emission extends over cool core Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Giant radio halo in the Coma cluster thermal X-ray emission radio synchrotron emission (Snowden/MPE/ROSAT) (Deiss/Effelsberg) Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Radio mini halo in the Perseus cluster radio synchrotron emission (Pedlar/VLA) thermal X-ray emission (ROSAT; NASA/IoA/A.Fabian et al.) Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Overview of diffuse radio phenomenon radio relics: αν ∼ 1 − 2.5, where jν ∝ ν −αν radio relic bubble: aged radio cocoon, steep spectrum radio phoenix: shock-revived bubble that has already faded out of the radio window → adiabatic compression? radio gischt: irregular morphology, at cluster periphery (< Mpc), in some cases coincident with weak X-ray shock, polarized → diffusive shock acceleration (Fermi I)? radio halos: centrally located, regular morphology, αν ∼ 1 − 1.5, unpolarized → volume filling radio emission giant radio halos: occur in merging clusters, > 1 Mpc-sized, morphology similar to X-rays radio mini halos: occur in cool core clusters, few times 100 kpc in size, emission extends over cool core Christoph Pfrommer Radio Phenomenon in Clusters Overview Observations Radio gischt emission Radio phenomenology Cosmic ray transport Radio gischt illuminates cluster shocks 2 2 2 2-2 -1 0 1 22 3 1 2 0 -1 0 -2 -2 0 -1 -1 -2 -2 y [ h-1 Mpc ] 1 hM ε̇diss i/hε̇diss i y [ h-1 Mpc ] 1 -1 0 1 2 -1 0 x [ h-1 Mpc ] 1 2 1 1 1 0 0 -1 -1 -2 -2 -2 -2 -2 -1 0 1 2 -1 0 x [ h-1 Mpc ] 1 2 Structure formation shocks triggered red/yellow: shock-dissipated energy, by a recent merger of a large galaxy blue/contours: 150 MHz radio gischt cluster. emission from shock-accelerated CRe Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Diffuse cluster radio emission – an inverse problem Exploring the magnetized cosmic web Battaglia, C.P., Sievers, Bond, Enßlin (2009): Combining the low-frequency radio observables of relics, we can probe strength and coherence scale of cluster magnetic fields diffusive shock acceleration of electrons existence and properties of the WHIM dynamical state of the cluster Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Population of faint radio relics in merging clusters Probing the large scale magnetic fields Finding radio relics with an FOF-finder that links radio emission instead of DM → relic luminosity function: 2 2 2 101 0 10-1 -1 0 0 10-1 -1 -1 1 1 y [ h-1 Mpc ] y [ h-1 Mpc ] 1 0 101 1 Sν [ mJy arcmin-2 ] 1 1 -1 10-2 -2 -2 -2 -2 -1 0 1 2 -1 0 x [ h-1 Mpc ] 1 2 10-3 10-2 -2 -2 -2 -2 radio map with GMRT emissivity threshold Christoph Pfrommer -1 0 1 2 -1 0 x [ h-1 Mpc ] 1 2 “theoretical” threshold (towards SKA) Radio Phenomenon in Clusters 10-3 Sν [ mJy arcmin-2 ] 2 Radio phenomenology Cosmic ray transport Overview Observations Radio gischt emission Relic luminosity function – theory Relic luminosity function → magnetic field behaviour and dynamical state: 10-2 10-1 Fν [mJy] for a cluster @ z ~ 0.05 100 101 102 103 104 10-2 10-1 Fν [mJy] for a cluster @ z ~ 0.05 100 101 102 ν = 150MHz, B0 = 5 µG αB = 0.3 αB = 0.5 αB = 0.7 αB = 0.9 104 B0 = 10 µG B0 = 5 µG B0 = 2.5 µG 10 Number of relics Number of relics 10 103 ν = 150MHz, αB = 0.5 1 25 1 26 27 log(Jν /Jν0 ), 28 29 30 31 32 Jν0 = 1 erg/Hz/s/ster varying magnetic decline with radius Christoph Pfrommer 25 26 27 log(Jν /Jν0 ), 28 29 30 Jν0 = 1 erg/Hz/s/ster varying overall magnetic strength Radio Phenomenon in Clusters 31 32 Overview Observations Radio gischt emission Radio phenomenology Cosmic ray transport Rotation measure (RM) RM maps and power spectra have the potential to infer the magnetic pressure support and discriminate the nature of MHD turbulence in clusters: arcmin 0 -5 5 5 75 0 -0.2 -75 -5 -0.4 10-6 1 P[RM](k) k2 [rad2 m-4] 0 RM [ rad m-2 ] 0.0 arcmin y [ Mpc ] 0.2 P[RM] (k) P[Bz] (k) 10 10-7 MFR1 MFR2 MFR3 10 1 -150 -0.4 -0.2 0.0 x [ Mpc ] 0.2 0.4 1 10 k [h Mpc-1] 100 Left: RM map of the largest relic, right: Magnetic and RM power spectrum comparing Kolmogorow and Burgers turbulence models. Christoph Pfrommer Radio Phenomenon in Clusters P[Bz](k) k2 [µG2 Mpc] P[RM](k) k2 [rad2 m-4] 150 0.4 Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Outline 1 Radio phenomenology Overview Observations Radio gischt emission 2 Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Which one is the simulation/observation of A2256? red/yellow: thermal X-ray emission, blue/contours: 1.4 GHz radio emission with giant radio halo and relic Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Observation – simulation of A2256 Clarke & Enßlin (2006) C.P. & Battaglia (in prep.) red/yellow: thermal X-ray emission, blue/contours: 1.4 GHz radio emission with giant radio halo and relic Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio halo theory – (i) hadronic model pCR + p → π ± → e± strength: all required ingredients available: shocks to inject CRp, gas protons as targets, magnetic fields predicted luminosities and morphologies as observed without tuning power-law spectra as observed weakness: all clusters should have radio halos does not explain all reported spectral features ... Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio halo theory – (i) hadronic model pCR + p → π ± → e± strength: all required ingredients available: shocks to inject CRp, gas protons as targets, magnetic fields predicted luminosities and morphologies as observed without tuning power-law spectra as observed weakness: all clusters should have radio halos does not explain all reported spectral features ... Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio halo and spectrum in the Bullet cluster Liang et al. (2000): SZ-corrected Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - X-ray luminosity 100.0 P1.4 GHz [1031 erg s−1 Hz−1 ] radio halos radio mini-halos 10.0 1.0 0.1 1 10 LX (0.1 − 2.4 keV) [1044 erg s−1 ] Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - X-ray luminosity 100.0 P1.4 GHz [1031 erg s−1 Hz−1 ] radio halos radio mini-halos 10.0 1.0 0.1 1 10 LX (0.1 − 2.4 keV) [1044 erg s−1 ] Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - X-ray luminosity 100.0 P1.4 GHz [1031 erg s−1 Hz−1 ] radio halos radio mini-halos 10.0 1.0 0.1 1 10 LX (0.1 − 2.4 keV) [1044 erg s−1 ] Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - central entropy P1.4 GHz [1031 erg s−1 Hz−1 ] 100.0 10.0 1.0 0.1 10 100 K0 [keV cm2 ] Christoph Pfrommer Radio Phenomenon in Clusters 1000 Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - central entropy P1.4 GHz [1031 erg s−1 Hz−1 ] 100.0 Cool cores Non−cool cores 10.0 1.0 0.1 10 100 K0 [keV cm2 ] Christoph Pfrommer Radio Phenomenon in Clusters 1000 Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - central entropy P1.4 GHz [1031 erg s−1 Hz−1 ] 100.0 10.0 1.0 0.1 10 100 K0 [keV cm2 ] Christoph Pfrommer Radio Phenomenon in Clusters 1000 Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio luminosity - central entropy P1.4 GHz [1031 erg s−1 Hz−1 ] 100.0 10.0 1.0 0.1 10 100 K0 [keV cm2 ] Christoph Pfrommer Radio Phenomenon in Clusters 1000 Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio phenomenology Cosmic ray transport Proton cooling times proton loss timescales, τ = E/Ė [Gyr] 104 103 hadronic ne = 10−4 cm−3 102 ne = 10−3 cm−3 101 ne = 10−2 cm−3 100 10-1 10-2 10-3 10-2 Coulomb 10-1 100 101 102 103 104 kinetic proton energy E [GeV] Christoph Pfrommer Radio Phenomenon in Clusters 105 Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio phenomenology Cosmic ray transport Proton cooling times proton loss timescales, τ = E/Ė [Gyr] 104 103 hadronic ne = 10−4 cm−3 102 ne = 10−3 cm−3 101 Hubble ne = 10−2 cm−3 100 10-1 10-2 10-3 10-2 Coulomb 10-1 100 101 102 103 104 kinetic proton energy E [GeV] Christoph Pfrommer Radio Phenomenon in Clusters 105 Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio halo theory – (ii) re-acceleration model strength: all required ingredients available: radio galaxies & relics to inject CRe, plasma waves to re-accelerate, . . . reported complex radio spectra emerge naturally clusters without halos ← less turbulent weakness: Fermi II acceleration is inefficient – CRe cool rapidly observed power-law spectra require fine tuning ... Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio halo theory – (ii) re-acceleration model strength: all required ingredients available: radio galaxies & relics to inject CRe, plasma waves to re-accelerate, . . . reported complex radio spectra emerge naturally clusters without halos ← less turbulent weakness: Fermi II acceleration is inefficient – CRe cool rapidly observed power-law spectra require fine tuning ... Christoph Pfrommer Radio Phenomenon in Clusters Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio phenomenology Cosmic ray transport Electron cooling times 104 electron loss timescales, τ = E/Ė [Gyr] 103 synchrotron + IC: B = 1 µG B = 3 µG 2 10 101 B = 10 µG Hubble 100 10-1 Coulomb: ne [cm−3 ] = 10−4 10−3 total loss 10−2 10-2 10-3 10-5 10-4 10-3 10-2 10-1 100 101 kinetic electron energy E [GeV] Christoph Pfrommer Radio Phenomenon in Clusters 102 Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio phenomenology Cosmic ray transport Electron cooling times 104 electron loss timescales, τ = E/Ė [Gyr] 103 synchrotron + IC: B = 1 µG B = 3 µG 2 10 101 B = 10 µG Hubble 100 10-1 Coulomb: ne [cm−3 ] = 10−4 10−3 total loss 10−2 10-2 10-3 10-5 10-4 10-3 10-2 10-1 100 101 kinetic electron energy E [GeV] Christoph Pfrommer Radio Phenomenon in Clusters 102 Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio phenomenology Cosmic ray transport Electron cooling times 104 electron loss timescales, τ = E/Ė [Gyr] 103 synchrotron + IC: B = 1 µG B = 3 µG 2 10 101 B = 10 µG Hubble 100 10-1 Coulomb: ne [cm−3 ] = 10−4 10−3 total loss 10−2 10-2 10-3 10-5 10-4 10-3 10-2 10-1 100 101 kinetic electron energy E [GeV] Christoph Pfrommer Radio Phenomenon in Clusters 102 Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Radio halos in low-luminosity clusters A challenge to the re-acceleration scenario or incomplete point source subtraction? A523 at 1.4 GHz (Giovannini+ 2011) Christoph Pfrommer P1.4 −LX relation with “outliers” Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Particle acceleration by turbulence or shocks? Diffuse low-frequency radio emission in Abell 521 (Brunetti et al. 2008) colors: thermal X-ray emission; contours: diffuse radio emission. “radio relic” interpretations with aged population of shock-accelerated electrons or shock-compressed radio ghosts (aged radio lobes), “radio halo” interpretation with re-acceleration of relativistic electrons through interactions with MHD turbulence. → synchrotron polarization is key to differentiate! Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Cosmic ray transport – magnetic flux tube with CRs Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Cosmic ray advection Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Adiabatic expansion and compression Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Cosmic ray streaming Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Expanded CRs Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Turbulent pumping Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Turbulent pumping Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Turbulent-to-streaming ratio Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Are CRs confined to magnetic flux tubes? Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Escape via diffusion: energy dependence Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality CR transport theory CR continuity equation in the absence of sources and sinks: ∂% ~ + ∇ · (υ %) = 0 ∂t υst = −υst υ = υad + υdi + υst ~ % ∇ ~ %| |∇ 1~ ∇% % η ~% = −κtu ∇ % η υdi = −κdi υad κtu = Ltu υtu 3 Enßlin, C.P., Miniati, Subramanian, 2011, A&A, 527, 99 Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality CR profile due to advection Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality CR density profile γtu = υυtu st Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality CR density at fixed particle energy γtu = υυtu st Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Gamma-ray emission profile pCR + p → π 0 → 2γ γtu = υυtu st Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Gamma-ray luminosity Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality pCR + p → π 0 → 2γ γtu = υυtu st Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality γ-ray limits and hadronic predictions (Ackermann et al. 2010) Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Eγ2 dFγ [GeV cm−2 s−1 ] dEγ γ-ray limits and hadronic predictions (Pinzke et al. 2011) CR-π0 10-8 Eγ = 1-10 GeV 10-9 10-10 A0085 10-11 3C129 dFγ [GeV cm−2 s−1 ] dEγ Eγ2 dFγ [GeV cm−2 s−1 ] dEγ A2142 A2029 0.4 A2199 A2163 0.6 A2256 0.8 1.0 Eγ = 1-10 GeV 10-9 10-10 A2319 10-11 A3376 A3266 0.0 Eγ2 A1914 A1689 0.2 CR-π0 10-8 A1367 A0754 0.0 CR-π0 10-8 A3888 A3571 0.2 Antlia AWM7 0.4 0.6 Coma Centaurus Hydra Fornax 0.8 1.0 Eγ = 1-10 GeV 10-9 10-10 10-11 M49 0.0 NGC4636 NGC5813 Norma Perseus Virgo NGC5044 NGC5846 Ophiuchus Triangulum 0.2 0.4 Christoph Pfrommer 0.6 0.8 Radio Phenomenon in Clusters 1.0 Radio phenomenology Cosmic ray transport Radio emission profile Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality pCR + p → π ± → e± → radio γtu = υυtu st Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Radio luminosity Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality pCR + p → π ± → e± → radio γtu = υυtu st Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Conclusions on cosmic ray transport streaming & diffusion produce spatially flat CR profiles advection produces centrally enhanced CR profiles → profile depends on advection-to-streaming-velocity ratio turbulent velocity ∼ sound speed ← cluster merger CR streaming velocity ∼ sound speed ← plasma physics → peaked/flat CR profiles in merging/relaxed clusters energy dependence of υstmacro → CR & radio spectral variations → outstreaming CR: dying halo ← decaying turbulence → bimodality of cluster radio halos & gamma-ray emission! Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Conclusions on cosmic ray transport streaming & diffusion produce spatially flat CR profiles advection produces centrally enhanced CR profiles → profile depends on advection-to-streaming-velocity ratio turbulent velocity ∼ sound speed ← cluster merger CR streaming velocity ∼ sound speed ← plasma physics → peaked/flat CR profiles in merging/relaxed clusters energy dependence of υstmacro → CR & radio spectral variations → outstreaming CR: dying halo ← decaying turbulence → bimodality of cluster radio halos & gamma-ray emission! Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Conclusions on cosmic ray transport streaming & diffusion produce spatially flat CR profiles advection produces centrally enhanced CR profiles → profile depends on advection-to-streaming-velocity ratio turbulent velocity ∼ sound speed ← cluster merger CR streaming velocity ∼ sound speed ← plasma physics → peaked/flat CR profiles in merging/relaxed clusters energy dependence of υstmacro → CR & radio spectral variations → outstreaming CR: dying halo ← decaying turbulence → bimodality of cluster radio halos & gamma-ray emission! Christoph Pfrommer Radio Phenomenon in Clusters Radio phenomenology Cosmic ray transport Observations and models CR pumping, streaming, and diffusion Radio and gamma-ray bimodality Literature for the talk Enßlin, Pfrommer, Miniati, Subramanian, 2011, A&A, 527, 99, Cosmic ray transport in galaxy clusters: implications for radio halos, gamma-ray signatures, and cool core heating Battaglia, Pfrommer, Sievers, Bond, Enßlin, 2009, MNRAS, 393, 1073, Exploring the magnetized cosmic web through low frequency radio emission Christoph Pfrommer Radio Phenomenon in Clusters
MBH–σv Relation
