The MAGIC telescope and the GLAST satellite

1. The MAGIC telescope and the GLAST satellite LAT (mass ~ 3000 kg) GBM (mass ~ 55 kg ) LAUNCH: ~ 2007 La Palma, Roque de los Muchacos (28.8° latitude - 17.8° longitude, 2225 m asl) INAUGURATION: 10/10/2003

2. THE NEXT GENERATION OF γ-RAY DETECTORS. • Ground based and satellite experiments are to some extent complementary for our purpose. • ACT detectors (MAGIC, HESS, VERITAS, CANGAROO): • limitate exposure times, • an upper energy threshold, • a very large effective area, • a medium energy resolution, • a point-likesurvey. • Satellite experiments (GLAST): • long exposure times, • a lower energy threshold, • a small effective area, • a good energy resolution, • a 4p survey.

3. MAGIC CharacteristicsEffective area 2,3 · 106cm2Energy resolution (σE/E) ~ 50% (10 GeV) ~ 20% (100 GeV)Angular resolution (σθ) ~ 0.05º (transverse) ~ 0.2º (longitudinal)Energy threshold ~ 30 GeV Field of view (sr) 4º Sensitivity 8 · 10-11 cm–2 s–1 GLAST CharacteristicsEffective area 104cm2Energy resolution (σE/E) 9% (100 MeV on-axis) <15% (10 - 300 GeV on-axis)Angular resolution (σθ) 3.37º (front), 4.64º (total) (100 MeV on-axis) 0.086º (front), 0.115º (total) (10 GeV on-axis) Energy threshold ~ 20 MeV Field of view (sr) 2.4 Sensitivity ( > 100 MeV) 3 · 10-9 cm–2 s–1

4. COMPARISON among gamma telescopes

5. COMPLEMENTARITY between the two experiments MAGIC a very large collection area GLAST very large field of view high duty cicle wide energy range excellent energy resolution low systematic energy calibration uncertainties (the new imaging Cherenkov telescopes are being built to slew within a few tens of seconds following notification) providing the ground-based observers with alerts for transient sources capability of detecting very short flares from known sources

6. GLAST’s observations of steady sources at the highest energies will be used to reduce the systematic errors in the sensitivities of the ground – based observatories. For individual point sources, MAGIC has unparalleled sensitivity at very high energies, with the ability to resolve shorter-duration flares. For many objects, full multiwavelenght coverage over as wide an energy range as possible will be needed to understand the acceleration and gamma-ray production mechanism. At energies above ~10 GeV, the spectra from distant AGNs may be cut off due to absorption by the extragalactic background light. Spectral measurements by bothGLAST & MAGIC will be needed to measure these absorptive effects accurately and thus determine the spectrum of the EBL from microwave to optical wavelenghts.

7. DETECTION PROSPECTS: Dark Matter • GLAST, with its good energy resolution, is favoured in observing the combined effect of the continuous component and the line; BUT • if Mχis higher than GLAST’s threshold MAGIC,owing to its larger effective area, is more adeguate for this purpose. LEP + MSUGRA:Mχ> 40 GeV

8. On the other hand: GLAST, with its wide angular acceptance, is an ideal instrument to measure eventual local enhancements in the γ-ray flux due to clumps of dark matter. The dependence on the profile which describes the dark matter distribution is in particular critical for detectors like MAGICwhich have a small angular acceptance; BUT If a large fraction of the total flux emitted is concentred in a tiny region of the sky, whose coordinates are known with sufficient accuracy, an ACT can be the ideal instrument for detecting neutralino dark matter.

9. Pulsar POLAR CAP MODELS: g-ray spectra cutoff very sharply, “superexponential” OUTER GAP MODELS: g-ray spectra cutoff more slowly, as a simple exponential POLAR CAP MODELS: g-ray spectra cutoff very sharply, “superexponential” GLAST: energy resolution, dynamic range MAGIC: energy threshold

10. DEVELOPMENTS