Author:
|
Aliu, E.; Barrio, J. A.; Bordas Coma, Pol; Bosch i Ramon, Valentí; Camara, M.; Contreras, J. L.; Cortina Blanco, Juan; Reyes, R. de los; Errando, M.; Miranda, J. M.; Moralejo, Abelardo; Nieto, D.; Oya, I.; Paredes i Poy, Josep Maria; Puchades, N.; Ribó Gomis, Marc; Sidro Martín, Núria; Tescaro, Diego; Zabalza de Torres, Víctor; Zanin, Roberta
|
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 γ-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed γ-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. |