Observation of Pulsed γ-Rays Above 25 GeV from the Crab Pulsar with MAGIC

• DOI: 10.1126/science.1164718
• Publication Date: 2008-10-17T01:11:20Z
• Authors: E. Aliu; H. Anderhub; L. A. Antonelli; P. Antoranz; M. Backes; C. Baixeras; J. A. Barrio; H. Bartko; D. Bastieri; J. K. Becker; W. Bednarek; K. Berger; E. Bernardini; C. Bigongiari; A. Biland; R. K. Bock; G. Bonnoli; P. Bordas; V. Bosch-Ramon; T. Bretz; I. Britvitch; M. Camara; E. Carmona; A. Chilingarian; S. Commichau; J. L. Contreras; J. Cortina; M. T. Costado; S. Covino; V. Curtef; F. Dazzi; A. De Angelis; E. De Cea del Pozo; R. de los Reyes; B. De Lotto; M. De Maria; F. De Sabata; C. Delgado Mendez; A. Dominguez; D. Dorner; M. Doro; D. Elsässer; M. Errando; M. Fagiolini; D. Ferenc; E. Fernandez; R. Firpo; M. V. Fonseca; L. Font; N. Galante; R. J. Garcia Lopez; M. Garczarczyk; M. Gaug; F. Goebel; D. Hadasch; M. Hayashida; A. Herrero; D. Höhne; J. Hose; C. C. Hsu; S. Huber; T. Jogler; D. Kranich; A. La Barbera; A. Laille; E. Leonardo; E. Lindfors; S. Lombardi; F. Longo; M. Lopez; E. Lorenz; P. Majumdar; G. Maneva; N. Mankuzhiyil; K. Mannheim; L. Maraschi; M. Mariotti; M. Martinez; D. Mazin; M. Meucci; M. Meyer; J. M. Miranda; R. Mirzoyan; M. Moles; A. Moralejo; D. Nieto; K. Nilsson; J. Ninkovic; N. Otte; I. Oya; R. Paoletti; J. M. Paredes; M. Pasanen; D. Pascoli; F. Pauss; R. G. Pegna; M. A. Perez-Torres; M. Persic; L. Peruzzo; A. Piccioli; F. Prada; E. Prandini; N. Puchades; A. Raymers; W. Rhode; M. Ribó; J. Rico; M. Rissi; A. Robert; S. Rügamer; A. Saggion; T. Y. Saito; M. Salvati; M. Sanchez-Conde; P. Sartori; K. Satalecka; V. Scalzotto; V. Scapin; T. Schweizer; M. Shayduk; K. Shinozaki; S. N. Shore; N. Sidro; A. Sierpowska-Bar...; A. Sillanpää; D. Sobczynska; F. Spanier; A. Stamerra; L. S. Stark; L. Takalo; F. Tavecchio; P. Temnikov; D. Tescaro; M. Teshima; M. Tluczykont; D. F. Torres; N. Turini; H. Vankov; A. Venturini; V. Vitale; R. M. Wagner; W. Wittek; V. Zabalza; F. Zandanel; R. Zanin; J. Zapatero; O.C. de Jager; E. de Ona Wilhelmi
• Keywords: 539.1; Acceleration; Electrónica (Física); 2202.03 Electricidad; FOS: Physical sciences; Electromagnetisme; Astrophysics; Space telescopes; 01 natural sciences; Magnetosfera; Emission; Electromagnetism; Very High Energy Gamma-ray Astronomy; Pulsar; MAGIC telescope; 537; Gamma ray astronomy; 0103 physical sciences; Outer Magnetosphere; Pulsar; Astronomia de raigs gamma; Slot Gaps; VHE gamma rays from Crab; Telescope; Pulsars; Radiation; Synchrotron radiation; Astrophysics (astro-ph); Search; Radiació sincrotrònica; 2207 Física Atómica y Nuclear; Nebula.; MAGIC; MAGIC; gamma-ray Imaging Cherenkov telescopes; VHE gamma rays from Crab; Púlsars; MAGIC telescope; Very High Energy Gamma-ray Astronomy; Magnetosphere; TEV; Electrónica; Física nuclear; Electricidad; Telescopis espacials; gamma-ray Imaging Cherenkov telescope

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.