MAGIC measurement of the Crab Nebula spectrum over three decades in energy

TL;DR

This paper presents a comprehensive gamma-ray spectrum of the Crab Nebula over three decades in energy, combining MAGIC and Fermi/LAT data, and discusses implications for nebula modeling and recent flare observations.

Contribution

First detailed spectrum spanning 50 GeV to 45 TeV for the Crab Nebula using MAGIC data with improved analysis techniques.

Findings

Precise measurement of the Inverse Compton peak.

Detection of Crab Nebula flares simultaneously with MAGIC and other observatories.

Insights into the nebula's magnetic field and electron energies.

Abstract

The Crab Pulsar Wind Nebula is the best studied source of $\gamma$-ray astrophysics. The contribution of the various soft radiation fields to the Inverse Compton component of its high energy emission, the strenght of the internal magnetic field and the maximum energies reached by primary electrons are however still matter of study. The MAGIC stereoscopic system recorded almost 50 hours of Crab Nebula data in the last two years, between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereo software provided an unprecedented differential energy spectrum spanning three decades in energy, from 50 GeV up to 45 TeV. At low energies, the MAGIC results, combined with the Fermi/LAT data, yield a precise measurement of the Inverse Compton peak. In addition, we present light curves of the Crab Nebula at different time scales, including a measurement simultaneous to one of the Crab Nebula flares recently detected by both Fermi/LAT and AGILE. Using the MAGIC spectrum together with multiwavelength data, we discuss the implications for the modeling of the Crab Nebula.