Summary

2. TeV gamma-ray astronomy with Cherenkov telescopes • MAGIC • Technical features • Results • LS I +61 303 • MAGIC as a neutrino telecope • Conclusions Summary

3. Gamma-ray GLAST (slightly magnified) Particle shower ~ 10 km ~ 1o Cherenkov Light ~ 120 m Cherenkov telescopes Collection area: ~ 105 m2 Important since gamma-rays at these energies are rare (1/m2 month)

4. Imaging technique Image intensity Primary energy Image orientation  Prim. direction Image shape  Primary nature

5. Stereoscopy Better determination Primary energy Primary nature Better signal/background discrimination

6. Cherenkov images are parameterized by the light distribution (shape, position and orientation) Image parameterization (1) Shape:g –rays are narrower than cosmic rays. (2) Orientation:g-rays point to the source: excess at small alpha Getting rid of the background (CR) ON: Pointing to source Crab Nebula g CR OFF: Pointing somewhere else

7. 17 m MAGIC is located at La Palma, Canary Islands (Northern Hemisphere) • The existing technology has been carried to the limit to improve sensitiity and lower the energy threshold: • The largest reflector, 17 m diameter → lowest energy threshold (100 GeV) • A 3.5 FOV camera with 577 PMTs (QE=30%) • An ultra-light structure (carbon-fiber) that allows for fast repositioning (40s) • Signal transmition through optical fiber to reduce noise • Dinamical mirror position correction thanks to a laser system • The existing technology has been carried to the limit to improve sensitiity and lower the energy threshold: • The largest reflector, 17 m diameter → lowest energy threshold (100 GeV) • A 3.5 FOV camera with 577 PMTs (QE=30%) • An ultra-light structure (carbon-fiber) that allows for fast repositioning (40s) • Signal transmition through optical fiber to reduce noise • Dinamical mirror position correction thanks to a laser system • The existing technology has been carried to the limit to improve sensitiity and lower the energy threshold: • The largest reflector, 17 m diameter → lowest energy threshold (100 GeV) • A 3.5 FOV camera with 577 PMTs (QE=30%) • An ultra-light structure (carbon-fiber) that allows for fast repositioning (40s) • Signal transmition through optical fiber to reduce noise • Dinamical mirror position correction thanks to a laser system • The existing technology has been carried to the limit to improve sensitiity and lower the energy threshold: • The largest reflector, 17 m diameter → lowest energy threshold (100 GeV) • A 3.5 FOV camera with 577 PMTs (QE=30%) • An ultra-light structure (carbon-fiber) that allows for fast repositioning (40s) • Signal transmition through optical fiber to reduce noise • Dinamical mirror position correction thanks to a laser system • The existing technology has been carried to the limit to improve sensitiity and lower the energy threshold: • The largest reflector, 17 m diameter → lowest energy threshold (100 GeV) • A 3.5 FOV camera with 577 PMTs (QE=30%) • An ultra-light structure (carbon-fiber) that allows for fast repositioning (40s) • Signal transmition through optical fiber to reduce noise • Dinamical mirror position correction thanks to a laser system • The existing technology has been carried to the limit to improve sensitiity and lower the energy threshold: • The largest reflector, 17 m diameter → lowest energy threshold (100 GeV) • A 3.5 FOV camera with 577 PMTs (QE=30%) • An ultra-light structure (carbon-fiber) that allows for fast repositioning (40s) • Signal transmition through optical fiber to reduce noise • Dinamical mirror position correction thanks to a laser system The MAGIC telescope

8. Active Mirror Control Super-light structure (65 t), to catch GRBs AMC and fast movement Jupiter before and after focusing

9. MAGIC-II: • Second telescope, completionin 2007 • Stereo  high purity gamma samples  better physics (lower threshold and better sensitivity) • MAGIC-1.5: • Running since February’07. • 2 GHz readout • Power of timing information under study MAGIC near future

10. PWN Pulsars Astrophysics Fundamental Physics AGNs Binaries mQSRs GRBs Physics with 100 GeV-10 TeV g-rays SNRs cosmological g-Ray Horizon Origin of CRs Cold Dark Matter Quantum Gravity effects

11. VHE g fluxes → upper limits to n fluxes (unless strong absorption) • km3n detectors sensitivity: F(>1TeV) = 10-11n/cm2s → Crab nebulag-ray flux • Shell type supernova remnants with ~1 Crab flux in g-rays: RAJ1713.7-3946 and RAJ0852.0-4622 best explained by hadronic interactions (extension, morphology, hard spectrum up to 100 TeV) • PWN: well explained by leptonic models but room for ions accelerated in the pulsar relativistic wind: Vela-X, Crab • Compact binary systems: LS5039 and LSI+61303. Lower n flux F(>1TeV) = 10-12n/cm2s or more depending on g-ray production region • VHE n’s messengers of non-thermal processes involving hadronic interactions • Ultimate proof of Galactic CR origin g p0 g p m p (TeV-PeV) p± nm nm + photo-meson interaction in high magnetic fields VHE n/g connection

12. PSR B1951+32 HESS J1834 • Observations from November 2004 to May 2006 • About 25% total observation time for Galactic targets (apart from Crab Nebula) • Targets include: • SNR: • Intense EGRET sources • HESS galactic scan sources (HESS J1834, HESS J1813) • PWN • Pulsars: limits to Crab, PSR B1957, PSR B1951 • Binaries/microquasars (low and high mass) • LS I +61 303 variable source • Galactic Center • HEGRA Unidentified TeV2032 • Cataclysmic variable (AE Aquari) Observation cycle I

13. LS I +61 303: • High Mass x-ray binary at a distance of 2 kpc • Optical companion is a B0 Ve star of 10.7 mag with a circumstellar disc • Compact object probably a neutron star • High eccentricity or the orbit (0.7) • Modulation of the emission from radio to x-rays with period 26.5 days attributed to orbital period • Secondary modulation of period 4 years attributed to changes in the Be star equatorial disc 0.4 AU 0.7 0.5 0.3 To observer LS I +61 303 0.9 0.2 0.1

14. LSI +61 303 Detected by MAGIC Hartman et al. 1999 LS5039 Detected by HESS • LSI was temptatively associated to an EGRET source (<10 GeV) EGRET sources

15. We observed LS I +61 303 with MAGIC for 54 horas between November 2005 and March 2006 (6 orbital cycles) LS I +61 303 by MAGIC Albert et al. 2006 • LS I +61 303 is a VHE gamma-ray emitter: • The flux is variable • It is modulated by the orbital motion (first indication of periodicity) • The peak of intensity is far from periastron • Results from another 4 orbital cycles obs. during fall 2006 published soon

16. MAGIC has observed LSI during 6 orbital cycles • A variable flux above 400 GeV (probability of statistical fluctuation 310-5) detected • Marginal detections at phases 0.2-0.4 • Maximum flux detected at phase 0.6 with a 16% of the Crab Nebula flux • More luminous at these energies than at x-rays • Energy spectrum from 200 GeV to 4 TeV is well fitted by a power law with spectral index a= -2.6, no cutoff seen Flux time variability Albert et al. 2006

17. Emission models • The broad-band experimental data on LSI may be explained both as produced by • relativistic jets (microquasar) • interaction of the winds of a young pulsar with that of the companion star. • In both cases the responsible may be accelerated electrons (Inverse Compton) or protons (pp interaction) → neutrinos!

18. t nt • Ultra-high energy t-neutrinos (PeV energies or more) can be looked for using MAGIC (Fargion 2002) • tlifetime is 50 m at 1 PeV (1015eV) and hundreds of km for 1 EeV (1018eV) • 83% of the times the decay produces air showers observable by MAGIC • Feasibility studies in MAGIC started this observation cycle • Data taking→ background studies (scattered light) • Preliminary Sensitivity studies: • MAGIC not competitive for diffuse neutrinos • Identified best source candidates: • LS I +61 303 • 1ES1959 • 1ES2344 • No “normal” observation time is lost since it is done when clouds do not allow them MAGIC as a neutrino telescope

19. New generation of Cherenkov telescopes are main actors of the recent burst of VHE astronomy • MAGIC has a major role with already 5 new discoveries and other interesting results • The compact binary system LS I +61 303 has been detected at TeV energies • The emission is variable • Possible hint of periodicity • The maximum of the emission happens 1/3 of the orbit away from periastron • The possibility of using MAGIC as a telescope for UHE neutrinos is under study Conclusions