1. Extreme Astrophysics the sky @ the sky @ > 10 GeV photon energy < 10 -14 cm wavelength > 10 8 TeV particles exist > 10 8 TeV particles exist they should not they should not more/better data more/better data arrays of air Cherenkov telescopes 10 4 km 2 air shower arrays km 3 neutrino detectors icecube.wisc.edu/~halzen

2. Energy (eV ) Radio CMB Visibe GeV  -rays 1 TeV Flux

3. Particle propagation in the Universe Photons: absorbed on dust and radiation; Protons/nuclei: deviated by magnetic fields, reactions with radiation (CMB) gammas (0.01 - 3 MLy) protons E>10 19 eV (30 MLy) protons E<10 19 eV neutrinos Cosmic accelerator

4.  +  CMB  e + + e - With 10 3 TeV energy, photons do not reach us from the edge of our galaxy because of their small mean free path in the microwave background.

5. Interaction length of protons in microwave background p +  CMB  + n   p = ( n CMB   ) -1  10 Mpc p +  CMB GZK cutoff energy > 5 10 7 TeV

6. Energy (eV ) Radio CMB Visible GeV  -rays Flux TeV sources! cosmic rays //////////////////////////////////

7. Multi-Messenger Astronomy protons,  - rays, neutrinos, gravitational waves as probes of the high-energy Universe protons: directions scrambled by magnetic fields  -rays : straight-line propagation but reprocessed in the sources, extragalactic backgrounds absorb E  > TeV neutrinos: straight-line propagation, unabsorbed, but difficult to detect 1. 2. 3.

8. New Window on Universe? Expect Surprises

9. the accelerators

10. LHC ~E -2.7 ~E -3 Ankle 1 part km -2 yr -1 knee 1 part m -2 yr -1 T. Gaisser 2005 Nature accelerates particles 10 7 times the energy of LHC! where? how? cosmic rays

11. Galactic and Extragalactic Cosmic Rays Knee Ankle extragalactic cosmic rays

12. the highest energies

13. ~10 2 Joules ~ 0.01 M GUT dense regions with exceptional gravitational force creating relativistic flows of charged particles, e.g. dense cores of exploding stars supermassive black holes merging galaxies Acceleration to 10 21 eV ?

14. solar flare shock acceleration Coronal mass ejection 09 Mar 2000

15. Cas A Supernova Remnant in X-rays John Hughes, Rutgers, NASA Shock fronts Fermi acceleration

16. Radiation Field: Radiation Field: Ask Astronomers Ask Astronomers Active Galaxy energy in protons ~ energy in electrons photon target observed in lines >> few events per year km 2

17. Fermi acceleration Jets Black Hole Accretion Disk Shock fronts Active Galactic Nucleus (Artist Impression)

18. Gamma Ray Bursts Protons and photons coexist in the fireball Fireball: Rapidly expanding collimated jet of photons, electrons and positrons becoming optically thin during expansion Shocks: external collisions with interstellar material (e.g. remnant— guaranteed TeV neutrinos!!!) or internal collisions when slower material is overtaken by faster in the fireball.

19. sources of the highest energy cosmic rays ?

20. Cosmic Accelerators E ~  qBM energy magnetic field boost factor mass E ~  qvBR R ~ GM/c 2

21. pulsar

22. E (eV) = B (Tesla) R 2 (m) 2  __ T ms-pulsarFermilab R10 km few km B10 8 Tfew T T -1 10 3 10 5 (#revs -1 ) E10 19 eV~10 12 eV = 1 TeV !

23. E ~  B M quasars  1 B  10 3 G M  10 9 M sun blasars  10 neutron stars   1  B  10 12 G M  M sun black holes. grb  10 2 emit highest energy  ’s! >~ >~ E > 10 19 eV ?

24. models of cosmic rays Bottom up –GRB fireballs –Jets in active galaxies –Accretion shocks in galaxy clusters –Galaxy mergers –Young supernova remnants –Pulsars, Magnetars –Mini-quasars –… Observed showers either protons (or nuclei) Top-down –Radiation from topological defects –Decays of massive relic particles in Galactic halo mostly pions (neutrinos, photons, not protons) Disfavored! Highest energy cosmic rays are not gamma rays Overproduce TeV-neutrinos

25. Top. Def. X,Y W,Z quark + leptons 10 24 eV = 10 15 GeV ~ M GUT topological defects ? (vibrating string, annihilating monopoles) heavy relics ? top-down spectrum hierarchy >>  >> p are cosmic rays the decay product of _

26. Georges Lemaitre believed that cosmic rays where primordial radiation from the Big Bang

27. detection of cosmic rays

28. Cosmic Rays Observations first discovered in 1912 by Austrian scientist Victor Hess, measuring radiation levels aboard a balloon at up to 17,500 feet (without oxygen!)

30. the Earth’s atmosphere as the detector Cherenkov radiation

31. cherenkov radiation: particle’s speed exceeds the speed of light

32. Copyright © 2001 Purdue University

33. How to Build a Detector Use the Phenomenon of Cherenkov light

34. ee 10 19 eV proton 6 km 12 km   +  - ++ ++ -- e+e+ e e + e - e+e+  00   e-e- p e+e+  

42. photonselectrons/positrons muonsneutrons

43. Akeno giant air Shower array AGASA ~ 100 km 2

44. Typical HiRes Stereo Events HiRes 1 HiRes 2

46. Mirror and Camera

47. HiRes in Utah Desert mirror

49. Typical HiRes Stereo Events HiRes 1 HiRes 2

50. Two Spectra: HiRes Mono and Fly’s Eye Stereo HiRes-1: 6/97-2/03 HiRes-2: 12/99-9/01 Excellent agreement between HiRes I and II. HiRes Stereo soon!

51. AGASA @#>?& !

52. Auger

54. fluorescence eye with active photodetectors (HiRes) ground array of particle detectors (AGASA) combine two succesful techniques

55. Augerarray

56. Galactic and Extragalactic Cosmic Rays Knee Ankle extragalactic cosmic rays 1 event km -2 yr -1

57. Measures number of shower particles at ground level... Ground Arrays Auger

58. the highest energies

59. Auger: on its way towards resolving the discrepancy

60. proton astro- nomy ? Pointing:  = ~=~= d ____ R gyro dB ___ E d ______ 1 Mpc B ______ 10 -9 G E _________ 3 x 10 20 eV  ___ 0.1 o ~=~= [ []] B ~ 10 -6 Gauss in local cluster?