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arXiv · 0809.2998

Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC

The MAGIC Collaboration·E. Aliu
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Abstract

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's 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 GeV. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 GeV, 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.

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The MAGIC Collaboration, E. Aliu. 2008-12-18. Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC. https://doi.org/10.1126/science.1164718

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