Development of Ideas in Ground-based Gamma-ray Astronomy, Status of Field and Scientific Expectations from HESS, VERITAS, MAGIC and CANGAROO Trevor C. Weekes Harvard-Smithsonian Center for Astrophysics

Development of (Ideas in Ground-based) Gamma-ray Astronomy, (Status of Field and) Scientific Expectations from HESS, VERITAS, MAGIC and CANGAROO by PAST(PRESENT)FUTURE

Beyond HESS/GLAST UCLA Development of MeV-GeV First Generation Systems 1960 – 1972 First Generation Systems 1960 – 1972 Spark Chambers Spark Chambers Balloons Balloons Controversy Controversy Second Generation Systems Second Generation Systems Spark Chambers Spark Chambers Small Satellites Small Satellites SAS-II, COS-B SAS-II, COS-B Third Generation Systems Third Generation Systems Spark Chamber Spark Chamber Bigger Bigger EGRET on CGRO EGRET on CGRO Fourth Generation Systems Fourth Generation Systems New Technology: Solid State New Technology: Solid State GLAST GLAST 100 MeV Sources One 30 (15) ,000? New Technology Increase in Size New Technology What?

Beyond HESS/GLAST UCLA Development of GeV-TeV First Generation Systems 1960 – 1985 First Generation Systems 1960 – 1985 Weak or no discrimination Weak or no discrimination Lebedev, Glencullen, Whipple, Narrabri, Crimea Lebedev, Glencullen, Whipple, Narrabri, Crimea Second Generation Systems 1985 – 2004 Second Generation Systems 1985 – 2004 Atmospheric Cherenkov Imaging Telescopes Atmospheric Cherenkov Imaging Telescopes Whipple, Crimea, CAT, HEGRA, Durham, CANGAROO Whipple, Crimea, CAT, HEGRA, Durham, CANGAROO …… …… Third Generation Systems 2004 – 2010 Third Generation Systems 2004 – 2010 Arrays of Large ACITs Arrays of Large ACITs MAGIC-2, HESS-5, CANGAROO-III, VERITAS-4 MAGIC-2, HESS-5, CANGAROO-III, VERITAS-4 Fourth Generation Systems Fourth Generation Systems TBD TBD TeV Sources Zero ~ 12 > ? New Technology Increase in Scale New Technology?

World Picture of ACIT TeV Observatories CANGAROO III, 4 tel., 2006 HESS, 4 tel., tel., 2007 VERITAS, tel. MAGIC, 1 tel., tel., 2008

Beyond HESS/GLAST UCLA European Collaboration; M.P.I (Heidelberg) 4 x 12 m Telescopes Completed in Dec. 2003; located in NAMIBIA HESS

Beyond HESS/GLAST UCLA CANGAROO III Four telescope system Four telescope system 10m diameter 10m diameter 100m spacing 100m spacing 427 pixel camera 427 pixel camera 0.17º spacing 0.17º spacing Woomera, S. Australia (31ºS 138ºE 160m a.s.l.) Woomera, S. Australia (31ºS 138ºE 160m a.s.l.) 4 telescopes not yet in full operation 4 telescopes not yet in full operation

MAGIC Telescope MAGIC Telescope MAGIC Telescope on La Palma (Oct.,2003) 17 aperture, new technology telescope Second Telescope in 2008; more new technology : First Large Telescope

Beyond HESS/GLAST UCLAVERITAS-4

H.E.S.S. Phase II Improved sensitivity above lower threshold (> 50 GeV) in coincidence mode 1.Improved sensitivity above lower threshold (50 GeV) in coincidence mode (stereo) 2.Test bed for telescopes (stereo) 3.Investigation of images/background in stand-alone mode at very low theoretical threshold (~ GeV) + MC

Beyond HESS/GLAST UCLA 1 GeV100 GeV GLAST (2 Years) VERITAS-4 (3  in 50 hrs) Whipple 10 m (3  in 50 hrs) DifferenDifferen DiDi Differential Flux Sensitivity

Beyond HESS/GLAST UCLA

Extrapolation: Solar Arrays 100 GeV Window of Opportunity closing Particle Arrays Milagro Tibet, ARGO Galactic Plane Extended Sources Transients Prompt GRBs

Beyond HESS/GLAST UCLA Extrapolation: HESS-5 Flux Sensitivity …x 2 improvement Reduced Energy CANGAROO-III Keep HESS honest MAGIC-2 High Tech (eventually) Reduced Energy VERITAS-4 (veritas) Keep MAGIC honest Surveys Mapping HESS-5 will be the dominant force in this era.

Beyond HESS/GLAST UCLA Overview of VERITAS Science Overview of VERITAS Science Active Galactic Nuclei Extragalactic Background Light Shell-type Supernova Remnants Gamma-ray Pulsars Plerions Gamma Ray Bursts Dark Matter (Neutralino Annihilation ) Galactic Diffuse Emission Unidentified Galactic EGRET Sources Lorentz symmetry violation Cosmic Ray Origin

Beyond HESS/GLAST UCLA Scientific Areas Astronomy and Astrophysics Cosmological Questions Origin of Cosmic Rays Physics

Beyond HESS/GLAST UCLA Future of GeV/TeV Gamma-ray Future of GeV/TeV Gamma-ray GLAST HESS SOURCES

Beyond HESS/GLAST UCLA Scientific Areas: After GLAST/HESS Astronomy and Astrophysics > 300 sources Old: SNR, AGN, Pulsars (GLAST), Dark Sources New: Clusters/Starburst /Others Cosmological Questions EBL Measured Distant Transients detected Origin of Cosmic Rays Sources (ACIT: HESS, veritas) Distribution (EAS: Milagro) Physics Dark Matter?? GRBs ?? Prompt: Milagro Delayed: MAGIC,veritas,HESS

Beyond HESS/GLAST UCLA Summary Ambition should exceed Expectations Carpe Diem Where are the Cosmologists? Space Astronomy after GLAST? Size counts: keep it small! An Observatory, not an Experiment One is good, two is better