PARTICLE ACCELERATION ON COSMOLOGICAL SCALES @HambObs MARCUS BRÜGGEN Abell 2744 Optical 1 Mpc Pearce+ (2017) Abell 2744 X-rays: intracluster mediumOptical (ICM) 1 Mpc Pearce+ (2017) Abell 2744 Radio: cosmicX-rays: rays intracluster (CR) + magnetic mediumOptical fields(ICM) 1 Mpc Pearce+ (2017) Abell 2744 Radio: cosmicX-rays: rays intracluster (CR) + magnetic mediumOptical fields(ICM) ~μGauss 1 Mpc Pearce+ (2017) Abell 2744 Radio: cosmicX-rays: rays intracluster (CR) + magnetic mediumOptical fields(ICM) ~μGauss radio spectra slope: spectral index (α) “flat” “steep” Diffuse cluster radio emission has a steep 1 Mpc spectrum Pearce+ (2017) DIFFUSE CLUSTER EMISSION JVLA 1-4 GHz latest reviews: Feretti+2012; Brunetti & Jones 2014 Pearce et al. (2017) 1.0 Mpc X-rays: 0.5-2.0 keV RELIC HALOS HALO • Mpc sizes, centrally located • Unpolarized Tailed radio galaxy • X-ray luminosity radio power correlation foreground AGN • Found in disturbed clusters DIFFUSE CLUSTER EMISSION JVLA 1-4 GHz latest reviews: Feretti+2012; Brunetti & Jones 2014 Pearce et al. (2017) 1.0 Mpc X-rays: 0.5-2.0 keV RELICS RELIC • Mpc sizes, cluster outskits • Elongated, filamentary morphologies • Polarized • Found in disturbed clusters HALOS HALO • Mpc sizes, centrally located • Unpolarized Tailed radio galaxy • X-ray luminosity radio power correlation foreground AGN • Found in disturbed clusters HOW DO YOU ACCELERATE PARTICLES? FERMI (1949): SCATTER OFF MOVING CLOUDS. VERY SLOW (V2/C2) BECAUSE CLOUDS BOTH APPROACH AND RECEDE IN SHOCKS, ACCELERATION IS 1ST ORDER IN V/C BECAUSE FLOWS ARE ALWAYS CONVERGING (BLANDFORD & OSTRIKER 78) FERMI I: SHOCKS: BOUNCING BETWEEN APPROACHING MAGNETIC MIRRORS FREE ENERGY: CONVERGING FLOWS ! $ N = N0E ! = ⁄%&' FERMI II: TURBULENCE: BOUNCING OF RANDOM MAGNETIC SCATTERERS Clusters grow through mergers MACS J0025.4MACS - 1222 Dark Dark Matter Matter Gas + Gas Galaxies Key S N Dark Dark Matter Matter Gas + Gas Galaxies Key S Gravitational Attraction N Dark Dark Matter Matter Gas + Gas Galaxies Key S N Dark Dark Matter Matter Gas + Gas Galaxies Key S N Dark Dark Matter Matter Gas + Gas Galaxies Key N+S Dark Dark Matter Matter Gas + Gas Galaxies Key Momentum N S Momentum Dark Dark Matter Matter Gas + Gas Galaxies Key Shocks Radio relics N C S Dark Dark Matter Matter Gas + Gas Galaxies Key PARTICLE ACCELERATION AT SHOCKS CIZA J2242.8+5301 •2 Mpc radio relic •additional fainter Radio relics X-rays •z = 0.19 •LX = 6 × 1044 erg/s van Weeren+ (2010, Science) Credit: van Weeren, MB, Chandra press Rajpurohit, Hoeft, van Weeren, MB et al. (2017) TOOTHBRUSHCOMPLICATED IS Rajpurohit, Hoeft, van Weeren, MB et al. (2017) AND HEREAND THE SPECTRAL INDEX... THE CENTRE OF THE MILKY WAY MeerKAT Collab. Radio relics Radio halos Shock (re)acceleration at Turbulent (re)acceleration in merger shocks merging galaxy clusters <latexit sha1_base64="9p2XLVaOdor+JrneuyoS3vTOSOQ=">AAAB63icbVDLSgNBEOyNrxhfUY+KDAbBU9gVRI9BLx4TMA9IljA7mU2GzMwuM7NCWHL06sWDIl79h3yHN7/Bn3A2yUETCxqKqm66u4KYM21c98vJrayurW/kNwtb2zu7e8X9g4aOEkVonUQ8Uq0Aa8qZpHXDDKetWFEsAk6bwfA285sPVGkWyXsziqkvcF+ykBFsMqlDDe4WS27ZnQItE29OSpXjSe378WRS7RY/O72IJIJKQzjWuu25sfFTrAwjnI4LnUTTGJMh7tO2pRILqv10eusYnVmlh8JI2ZIGTdXfEykWWo9EYDsFNgO96GXif147MeG1nzIZJ4ZKMlsUJhyZCGWPox5TlBg+sgQTxeytiAywwsTYeAo2BG/x5WXSuCh7l2W3ZtO4gRnycASncA4eXEEF7qAKdSAwgCd4gVdHOM/Om/M+a80585lD+APn4wf3JJHj</latexit> fraction η of KE dissipated at Energy is injected on large scales shock by DM-driven mergers. <latexit sha1_base64="9p2XLVaOdor+JrneuyoS3vTOSOQ=">AAAB63icbVDLSgNBEOyNrxhfUY+KDAbBU9gVRI9BLx4TMA9IljA7mU2GzMwuM7NCWHL06sWDIl79h3yHN7/Bn3A2yUETCxqKqm66u4KYM21c98vJrayurW/kNwtb2zu7e8X9g4aOEkVonUQ8Uq0Aa8qZpHXDDKetWFEsAk6bwfA285sPVGkWyXsziqkvcF+ykBFsMqlDDe4WS27ZnQItE29OSpXjSe378WRS7RY/O72IJIJKQzjWuu25sfFTrAwjnI4LnUTTGJMh7tO2pRILqv10eusYnVmlh8JI2ZIGTdXfEykWWo9EYDsFNgO96GXif147MeG1nzIZJ4ZKMlsUJhyZCGWPox5TlBg+sgQTxeytiAywwsTYeAo2BG/x5WXSuCh7l2W3ZtO4gRnycASncA4eXEEF7qAKdSAwgCd4gVdHOM/Om/M+a80585lD+APn4wf3JJHj</latexit> <latexit sha1_base64="CRfNKE/UARSBTcPLgVw6JzH3KNo=">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</latexit> fraction η of turbulent energy 1 3 <latexit sha1_base64="SFRtry6Pdy1S9iZSQ2N80LUK5yg=">AAACGXicbVDLSgMxFM34tr6qLt0Ei+CqzCiiy6obERcK9gGdWjJppo3NJENyp1CG+Y1u/BU3LhRxqSu/wZ8wbV1o64GQk3Pu5eaeIBbcgOt+OjOzc/MLi0vLuZXVtfWN/OZWxahEU1amSihdC4hhgktWBg6C1WLNSBQIVg2650O/2mPacCVvoR+zRkTakoecErBSM+/6DIgfakJTX3cU7jXtHWHI7g6z9Gr84PI+y7BPWwpwpZkvuEV3BDxNvB9SKJ0OrkqX+uu6mX/3W4omEZNABTGm7rkxNFKigVPBspyfGBYT2iVtVrdUkoiZRjraLMN7VmnhUGl7JOCR+rsjJZEx/SiwlRGBjpn0huJ/Xj2B8KSRchknwCQdDwoTgUHhYUy4xTWjIPqWEKq5/SumHWJjAhtmzobgTa48TSoHRe+o6N7YNM7QGEtoB+2ifeShY1RCF+galRFFA/SIntGL8+A8Oa/O27h0xvnp2UZ/4Hx8A1gwpCA=</latexit> νPsync = η Aρvsh 3 2 <latexit sha1_base64="R5Nuqo0RdAq+I6big6I/r0HEq6k=">AAAB9HicbVDLSsNAFL2pr9r6qLp0M1gFVyURRDdC0Y3LCvYBbSiT6aQdOpPEmUkhhH6HGxeKuHXpD/gH7vwQXTtNu9DWAxcO59zLvfd4EWdK2/anlVtaXlldy68XihubW9ulnd2GCmNJaJ2EPJQtDyvKWUDrmmlOW5GkWHicNr3h1cRvjqhULAxudRJRV+B+wHxGsDaSW+umHSmQSgIyvuiWynbFzoAWiTMj5erh19v7qPhd65Y+Or2QxIIGmnCsVNuxI+2mWGpGOB0XOrGiESZD3KdtQwMsqHLT7OgxOjJKD/mhNBVolKm/J1IslEqEZzoF1gM1703E/7x2rP1zN2VBFGtq3soW+TFHOkSTBFCPSUo0TwzBRDJzKyIDLDHRJqeCCcGZf3mRNE4qzmnFvjFpXMIUediHAzgGB86gCtdQgzoQuIN7eIQna2Q9WM/Wy7Q1Z81m9uAPrNcfWwCWQQ==</latexit> ρvt Psync = η V Linj · <latexit sha1_base64="WrzoeerILmljPWQ5zQY/DreHbXM=">AAACAnicbVDLSgMxFM3UV62vUVeiSLAIblpmlKLLohuXLdgHdMaSSdM2NJkZkoxQhsGNfoobF4q46cKvcOc3+BOm0y609cDlHs65l+QeL2RUKsv6MjILi0vLK9nV3Nr6xuaWub1Tl0EkMKnhgAWi6SFJGPVJTVHFSDMUBHGPkYY3uBr7jTsiJA38GzUMictRz6ddipHSUtvcc4hC0JGUQ9u6jQulpJD2s6Rt5q2ilQLOE3tK8uWDUfX78XBUaZufTifAESe+wgxJ2bKtULkxEopiRpKcE0kSIjxAPdLS1EecSDdOT0jgsVY6sBsIXb6Cqfp7I0ZcyiH39CRHqi9nvbH4n9eKVPfCjakfRor4ePJQN2JQBXCcB+xQQbBiQ00QFlT/FeI+EggrnVpOh2DPnjxP6qdFu1S0qjqNSzBBFuyDI3ACbHAOyuAaVEANYHAPnsALeDUejGfjzXifjGaM6c4u+APj4wdVPZko</latexit> 5 3 η 10− 10− ∼ − Botteon et al. 2020 TESTS OF FERMI I PROBLEM #1: WHY IS THE ACCELERATION SO EFFICIENT? PROBLEM #2: WHERE DOES THE B-FIELD COME FROM? PROBLEMS WITH SHOCK ACCELERATION Low Mach number shocks and luminous relics → Macario+(2011); Vazza • & Brüggen (2014); van Unrealistic fraction of shock energy transferred Weeren+(2016) into relativistic electrons Ogrean+ (2014); •Mismatch between spectral index and Mach Akamatsu+ (2013) number •No γ-rays from relics: relative acceleration efficiency of electrons and protons different from Vazza+ (2014,2015,2016) DSA RELICS: ORIGIN OF CR ELECTRONS Shock acceleration •Particles accelerated via diffusive shock acceleration acceleration (DSA / SDA) •Start from the thermal pool Ensslin+ (1998); Blandford & Eichler (1987); Guo+ (2014); Caprioli & Spitkovsky (2014) van Weeren+ (2017) Re-acceleration •Similar to DSA but start with seed fossil relativistic electron population (DSRA) •More efficient re-acceleration for Markevitch+ (2005); low-Mach shocks (compared to DSA) Giacintucci+ (2008); Kang+ (2012, 2016); •Additional models proposed Shimwell+ (2015); GMRT 610 MHz (Fermi-II type) Bonafede+ (2014) Chandra Fujita+(2015) Botteon+ (2016) Vazza, MB + 2021 Rudnick, MB+ 2021 MAGNETIC FIELD? SMALL-SCALE DYNAMO LOFAR Onsala Birr Irbene Dutch stations Chilbolton Norderstedt Bałdy Potsdam Borówiec Jülich Efelsberg Tautenburg Łazy Nançay Unterweilenbach Medicina GOING DEEP A2255 has been chosen as the first LOFAR Cluster Deep Field Botteon, MB, et al. (2020) MEGAHALOS ABELL 665 Cuciti et al. (in prep) Questions • How common are Megahalos? • What is the relation between Megahalos and radio galaxies inside the cluster? • What is the relation between Megahalos and classical radio halos? BRIDGES Why are radio bridges interesting? The non-thermal cosmic web Stochastic acceleration • Bridges contain plenty of turbulent power ~ 1045 erg /s • ~ 0.01% is enough to explain radio power • Turbulence is super-Alfvenic (MA ~10) and solenoidal (>50%) • Fermi-II-like acceleration mediated by solenoidal turbulence (Brunetti & Vazza, 2020) • Predictions: • Low-frequency emission is smooth • High-frequency emission is clumpy • Bright phase is < 0.5 Gyr long 2 Mpc 2 Mpc 2 Mpc 0.000000 0.000004 0.000014 0.000035 0.000079 0.000174 0.000381 0.000827 0.001789 0.003842 Continuum emission from bridges between clusters LOFAR 140 MHz LOFAR + Planck Weak shocks or volume-filling turbulence? Only detected by LOFAR no spectrum. Govoni, MB, et al. (2019) The bridge in the Coma cluster seen with LOFAR Halo front Streams Bonafede, MB, et al. (2020) Turbulent power in bridge volume V: If group injects turbulence A fraction can be converted to mildly relativistic electrons: where Mach number of turbulence for given efficiency For radio halos so is enough to power radio bridge Bonafede, MB, et al. (2020) A giant radio bridge connecting two galaxy clusters in Abell 1758 Emission is volume-filling Botteon et al. (2019) ART-XC (IKI) Navigator (NPO Lavochkin) eROSITA (MPE) Спектр-РГ Navigating the eROSITA X-ray sky Coma Cluster Sco X-1 z=3.1 QSO [26 Gpc] Cygnus Cyg X-1 [99 Mpc] [2.8 kpc] Virgo Cluster [17 Mpc] Shapley Supercluster Superbubble [1.9 kpc] [200 Mpc] Cas A [1-2 kpc] Centaurus Cluster [3.4 kpc] [41 Mpc] Crab Pulsar [~2 kpc] North Polar Spur Orion Nebula G156.2+05.7 [412 pc] Vela