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Explore the phenomenon of cosmic accelerators and high energy particles in astrophysics, including cosmic ray spectra, shock acceleration, and the search for cosmic ray sources. Discover the latest research on neutrinos and gamma rays from cosmic ray sources.
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Cosmic Accelerators Astrophysics with High Energy Particles Graduiertenkolleg “Physik an Hadronen-Beschleunigern” Klausurtagung, 17.10.2006 Thomas Lohse Humboldt University Berlin
The Cosmic Ray Spectrum E2.7, mostly protons Knee solar modulation transition to heavier nuclei E3.1 mostly Fe? Ankle transition to lighter nuclei? Power Laws Shock Acceleration predicts FSource E2 ? Direct Measurements Discovery Balloon Flight Victor Hess, 1912 EAS Detectors
Open questions after 90 years • What and where are the sources? • How do they work? • Are the particles really accelerated?... • …or due to new physics at large mass scales? • And how do cosmic rays manage to reach us?
p p 0 e Inverse Compton (+Bremsstr.) radiation fields and matter Production in Cosmic Accelerators protons/nuclei electrons/positrons
Primary (Hadron,Gamma) Air Shower Fluorescence Detector Fluorescence Č Hadron-Detector Č-Telescope Scintillator or Water Č R&D Radio-Detection Acoustic-Detection Atmospheric (4) ,e, InstrumentedWater / Ice Primary (4) Experimental Techniques ( E 10 GeV )
Outline • Cosmic rays beyond the ankle • Neutrinos from cosmic ray sources • Gammas from cosmic ray sources Outline • Cosmic rays beyond the ankle • Neutrinos from cosmic ray sources • Gammas from cosmic ray sources
p(100 EeV) p E3FE cut-off reprocessed p 1018 1019 1020 EeV Greisen-Zatsepin-Kuzmin Cut-Off: Energy loss in cosmic microwave background (CMB) p(100 EeV) + (CMB) p + , n + p beyond ankle p below ankle isotropized in B-fields
AGASA HIRes Fly’s Eye model fit to HIRes data triplet Spectra consistent allowing for 30% systematic energy shift… AGASA: surface detector array HIRes: fluorescence light detector no GZK cut-off? AGASA
The Pierre Auger Project 3000 km2 Hybrid Detector 4 Fluorescence Sites 1600 Water Č-Detectors 75% installed AGASA
Clean EeV Hybrid Events contemporaneous atmospheric monitoring Energy Calibration of Surface Detectors statistically limited up to now… 14% duty cycle Present systematics: Calibration 12% Fluorescence yield 15% • calorimetric measurement • independent of primary composition • independent of air shower details
Power Law Fit systematic errors First Look at 3EeV Energy Spectrum (from surface detector array) Data: Jan. 2004 – Jan 2005 Exposure: 1750 km2 sr yr AGASA + 7% Events: 3525
AUGER best fit preliminary Calibration uncertainty
Cosmic rays beyond the ankle • Neutrinos from cosmic ray sources • Gammas from cosmic ray sources
The Main Players presently: • Amanda/IceCube, South Pole Ice • BAIKAL, Water of Lake Baikal • + future Mediterranean detectors IceCube (in construction) South Pole Dome AMANDA Summer camp 1500 m Amundsen-Scott South Pole Station 2000 m [not to scale]
1:1:1 flavour flux ratio AMANDA 1: B10, 97, ↑μ 2: A-II, 2000, unfold. 3: A-II, 2000, casc. 4: B10, 97, UHE Baikal 5: 98-03, casc. upward (2 coverage) atmospheric horizontal E2-Flux Limit vertical preliminary IceCube 3 years all-flavour limits Search for Diffuse Cosmic Neutrinos add directional & temporal constraints …
90 Significance Sky Map 24h h max. excess from random skymaps Maximum Excess 3.4 3.4 92% 90 Unbinned Search for Clusters AMANDA 2000-2003 preliminary
time window: 40 / 20 days • angular bin: 2.25°-3.75° • fixed a priori sliding window events time AMANDA Search for Transient Sources 12 Objects tested (over 4 years), no triplets found … BUT … …
The first cosmic ray neutrino ??? 66 day triplet 5 events dublet window background WHIPPLE E>0.6TeV HEGRA E>2TeV Orphan -flare (not seen in X-rays) AMANDA – 1ES1959+650 – 2.25o search bin size revisited a posteriori • Statistical significance hard to tell … but promising! • Lessons learned: Multimessenger & multiwavelength studies important. Use -ray flares (not only X-rays)…
Cosmic rays beyond the ankle • Neutrinos from cosmic ray sources • Gammas from cosmic ray sources
Veritas MAGIC in construction H.E.S.S. CANGAROO III Cherenkov Telescopes (3rd Generation)
But what about hadrons (protons and nuclei)? Pulsar Wind Nebula: Electron wind from centralpulsar heats the cloud Synchrotron radiation The Standard Candle for TeV -Astronomy Crab Supernova 1054 a.D. d = 2 kpc optical 1 lightyear
Cassiopaeia A Supernova 1658 a.D. d = 2,8 kpc X ray picture • “Shell Type” SNR: • no electron wind from pulsar • gamma signal from shell regions not totally drowned in that of electron wind • good source class to observe hadron acceleration
RX J1713.73946 RX J1713.73946 E 210 GeV H.E.S.S. 2004 E 210 GeV H.E.S.S. 2004 resolution resolution First Resolved Supernova Shells in -Rays RX J0852.04622 H.E.S.S. 2005 E 500 GeV Strong correlation with X-ray intensities • SN-Shells are accelerating particles up to at least 100TeV! • But are these particles protons/nuclei or electrons?
Matter Density B Ee Stars Dust Cosmic Proton Accelerators Cosmic Electron Accelerators CMB B Ee Inverse Compton Synchrotron Radiation 0 Synchrotron Radiation of Secondary Electrons Electron or Hadron Accelerator? radio infrared visible light X-rays VHE -rays E2 dN/dE log(E)
B7,9,11G 2.0,2.25,2.5 EGRET 2.0 B10G Electron accelerator fits for RX J1713.73946: • Continuous electron injection over 1000 years • Injection spectrum: power law with cutoff H.E.S.S. • large & injection rate bremsstrahlung important • needs tuning at low E • IC peak not well described • B-field low for SNR shell
RX J1713.73946 H.E.S.S. Proton accelerator fit: • Continuous proton injection over 1000 years • Injection spectrum: power law, index 2 • Different cutoff shapes & diffusion parameters
3.2. Inner Glactic Plane 30 ≲l ≲ 30 3 ≲b ≲ 3
Galactic Centre HESS J1745290 HESS J1632478 HESS J1825137 RX J1713.73946 HESS J1616508 HESS J1837069 HESS J1804216 HESS J1745290 HESS J1708410 HESS J1834087 HESS J1813178 HESS J1614518 G0.90.1 HESS J1747281 HESS J1713381 HESS J1634472 HESS J1640465 HESS J1702420 HESS J1804-216 HESS J1834-087 HESS J1640-465 H.E.S.S. Scan of Inner Galactic Plane 5 SNR 3 Pulsar 3 ??? 14 new sources, all extended! Possible counterparts: (plus previously known ones) Resolution
… a new source class: “Dark Accelerators” • extended • hard spectra, • steady emission TeV-Gamma-Ray Radio X-Ray Five sources known: TeV J20324130 (HEGRA) HESS J1303631 HESS J1614518 HESS J1702420 HESS J1708410 What are these sources? Are they hadron accelerators?
Galactic Centre HESS J1745290 HESS J1632478 HESS J1825137 RX J1713.73946 HESS J1616508 HESS J1837069 HESS J1804216 HESS J1745290 HESS J1708410 HESS J1834087 HESS J1813178 HESS J1614518 G0.90.1 HESS J1747281 HESS J1713381 HESS J1634472 HESS J1640465 HESS J1702420 3.3. Galactic Centre
Systematic pointing error Chandra GC survey NASA/UMass/D.Wang et al. Chandra GC survey NASA/UMass/D.Wang et al. CANGAROO (80%) CANGAROO (80%) Sgr A East SNR H.E.S.S. (95%); MAGIC similar H.E.S.S. H.E.S.S. Whipple (95%) Whipple (95%) Radio Contour Contours from Hooper et al. 2004 Sgr A* Radio Galactic Centre: A pointlike TeV- source • Astrophysical Source Candidates: • 3106 M⊙black hole Sgr A • EMF close to rotating black hole • Accretion shocks • Supernova Remnant Sgr A East • Expanding shock waves
… or maybe dark matter annihilation ? Crab GC MAGIC H.E.S.S. • no visible cut-off rather large mass • measured flux large cross-section and/or DM density 20 TeV Neutralino 20 TeV Kaluza Klein particle … unlikely !
Galactic Centre Neighbourhood SNR G0.90.1 HESS J1747281 Galactic Centre HESS J1745290 EGRET GeV--sources ~150 pc
HESS J1745290 Galactic Centre Neighbourhood ...point sources subtracted • first resolved detection of diffuse TeV--radiation • cosmic rays (hadrons) interacting with molecular clouds molecular clouds density profiles ~150 pc
diffuse radiation expected flux for CR spectrum observed on earth Cosmic Ray Spectrum at the GC... is very different from the one at earth Cosmic rays are much harder and have 3 larger density around the GC Possible reason: Close-by source population Possibly single SN-explosion
Blazars • General Active Galactic Nuclei (AGN): • Supermassive black holes, M 109 M • accretion disk and relativistic jets • Blazar-Typ: Jet points towards the earth • Doppler-boost TeV -radiation
e+ e- dN/dE dN/dE E E Absorption in (infrared) extragalactic background light (EBL) (TeV) + (EBL) e+e- Measurement of EBL ( Cosmology) Physics of compact objects, acceleration/absorption in jets,…
Cut-off Energy and -Ray Horizon PG 1553113
EBL Hardest plausible source spectrum = 1.5 EBL Unfolding of Measured Spectra Too much EBL 1 ES 1101 = 2.9±0.2 H 2356 (x0.1) = 3.1±0.2 H 2356 (x 0.1) G = 3.1±0.2 Preliminary
excluded by H.E.S.S. Assumed shape for rescaling H.E.S.S. upper bound fromspectral shapes of 1ES 1101-232 (z = 0.186) H 2356-309 (z = 0.165) New Upper Bound on EBL Density EBL density seems 2 smaller than expected! Little room for EBL sources other than galaxies (early stars…) Direct IRTS Measurements Upper Limits Lower Limits (Galaxy Counts)
Summary • Cosmic ray puzzle persists…but is under pressure by massive attack from EAS-arrays, - and -telescopes • Progress in understanding knee, ankle and GZK-region AUGER data disfavour small scale anisotropies • Cosmic -detection in multi-messenger campaigns? • Neutrino astronomy might start sooner than expected! • Major break-through in TeV--astronomy • supernova shells are 100TeV accelerators • large population of extended galactic TeV sources discovered • first microquasar-candidates established as TeV accelerator • diffuse galactic TeV emission (Milagro, H.E.S.S.) • TeV- from Active Galactic Nuclei at large red-shifts, …
Supernovae AGN Pulsars Dark Accelerators Microquasars Black Holes Gamma Ray Bursts The Cosmic Accelerator Cocktail ?