One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.

E., A., H., A., L. A., A., P., A., M., B., C., B., et al. (2008). Observation of pulsed gamma-rays above 25 GeV from the Crab pulsar with MAGIC. SCIENCE, 322(5905), 1221-1224 [10.1126/science.1164718].

Observation of pulsed gamma-rays above 25 GeV from the Crab pulsar with MAGIC

BONNOLI, GIACOMO;MEUCCI, MARIO;PAOLETTI, RICCARDO;STAMERRA, ANTONIO;TURINI, NICOLA;
2008-01-01

Abstract

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.
E., A., H., A., L. A., A., P., A., M., B., C., B., et al. (2008). Observation of pulsed gamma-rays above 25 GeV from the Crab pulsar with MAGIC. SCIENCE, 322(5905), 1221-1224 [10.1126/science.1164718].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/25547
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