High Energy  -rays Roger Blandford KIPAC Stanford

22 ii 08P52 The Electromagnetic Spectrum r mm smm irouvx  100neV 100TeV mec2mec2 m p c 2 High Energy  -rays 1GeV

22 ii 08P53 Multi-Messenger Science Electromagnetic Cosmology Gravitational Radiation Dark Matter Neutrinos eV eV Hubble Planck Cosmic Rays High Energy  -rays Strong Scientific Synergy

22 ii 08P54 Gamma Ray Astrophysics GeV observations from space –Direct detection SAS-2 -> CosB -> EGRET -> GLAST TeV observations from ground –Atmospheric Cerenkov Whipple -> HESS/MAGIC/VERITAS ->… –Water Cerenkov Milagro ->…

22 ii 08P55 GLAST Joint NASA-DOE-Italy- France-Japan- Sweden, Germany… mission Launch May –Cape Canaveral Success of GLAST is top priority x EGRET; high energy extension –Future program likely ground-based for a while

22 ii 08P56 GLAST LAT GeV 2.5 sr, m 2 5 o - 5’resolution  ln E ~ x cm -2 s -1 (>0.1 GeV, point source) 10 9 photons (3Hz) All sky every 3hr Sources after a decade? 10,000 Active Galactic Nuclei 1000 Gamma Ray Bursts 100 Pulsars 100 Supernova Remnants 10 Galaxies 10 Clusters of Galaxies 10 X-Ray Binaries ? Unidentified Sources GBM MeV 9sr, 100 cm 2. 1 o resolution  ln E ~ 0.1 Combine with Swift

22 ii 08P57 Exploring the Terascale VERITAS (NSF+DOE+Smithsonian) H.E.S.S. (2) MAGIC x 2 Milagro ~10 ns flash ~1 10 km->10 4 m 2 Stereo imaging ~ TeV ~5 o field of view ~5’ PSF per photon ~100 sources ~1-10 TeV

22 ii 08P58 Hadrons vs Leptons vs WIMPS (Pions vs Compton vs Annihilation) Hadrons? Leptons? WIMPs? X-ray vs TeV Fermi acceleration at shocks Magnetic field amplification Origin of cosmic rays? Many puzzles remain GLAST will interpolate Relativistic jets created by massive black hole in galactic nuclei Gamma ray emission at small radii Inverse Compton radiation 2 min variability EM -> L -> H ? UHECR? If DM is cosmologically-generated, weakly interacting particle, there may be detectable annihilation from Galactic center and dwarf galaxies. Constraints will be combined with results from LHC and underground direct searches. Must understand diffuse background!

22 ii 08P59 Cosmic Accelerators Stochastic accelerationUnipolar induction uu / r B u B L  Shocks transmit power law distribution f(p) ~ p -3r/(r-1) Also second order processes  V ~  I ~ V / Z 0 P ~ V I Neutron stars Black holes V ~ TeV - ZeV I ~ 10 GA - 10 EA UHECR?

22 ii 08P510 Gamma Ray Bursts SN energy in seconds –Birth cry of stellar black hole? Special supernovae –Binary NS merger?? LIGO! –NS magnetosphere flare (10 15 G) Environmental impact Ultrarelativistic outflow –“AGN on speed” –  opacity used to understanding sources Across the universe –Cosmological probes Expect Unscripted Discoveries

22 ii 08P511 Future TeV Options ~ TeV ~ 50 telescopes Large FOV ~1’ PSF per photon ~10 x VERITAS sensitivity ~ $100M class Exploring cheaper detectors DAQ trailer Road HAWC Tank Array in GEANT m (30 tanks) AGIS/CTA ~1-100 TeV ~15 x Milagro Improved rejection Wide field Large duty cycle $10M class HESS/VERITAS Simulation AGIS/CTA Simulation Technology and scientific trade studies underway-> decadal survey x sources DM, LI studies Unexpected

22 ii 08P512 Cultural Observations Particle physicists, astrophysicists collaborating very well. –Organized more like HEP –Interagency collaboration “debugged” Common detector technology –GLAST: Si tracking technology… –AGIS/CTA: photodetectors, fast electronics, triggers, computing… Proven signals –cf DM, GW, VHE  axion… searches Excellent, hands on training for students and postdocs –Fabrication and data analysis

22 ii 08P513 Gamma-ray Physics discover the nature of cosmic accelerators and monitor galaxy growth and development seek annihilation signature of supersymmetry particles in combination with LHC, underground check validity of Lorentz invariance over cosmic distances attract and train students who will be needed to work on future detectors and their data GLAST IACT HAWC …understand how our universe works at its most fundamental level …discovering the most elementary constituents of matter and energy …exploring the basic nature of space and time itself …development of key technologies and trained manpower DoE/HEP Mission High Energy  -rays

22 ii 08P514 Summary Golden age of Cosmic HE  -rays –Support GLAST, VERITAS as they solve classic astrophysical problems and explore fundamental physics Next phase will be just as exciting and is (relatively) inexpensive and quick –Invest in the future now