Observation of the Crab Nebula with the MAGIC telescope

TL;DR

This paper reports detailed VHE gamma-ray observations of the Crab Nebula with the MAGIC telescope, measuring its spectrum, flux, and spatial characteristics, and constraining the pulsar's gamma-ray emission and spectral cutoff energies.

Contribution

First detailed VHE gamma-ray spectrum measurement of the Crab Nebula with the MAGIC telescope, including flux, spectral shape, and spatial analysis, and constraints on pulsar emission.

Findings

Gamma-ray flux measured between 60 GeV and 9 TeV.

Spectrum described by a curved power law with specific parameters.

No pulsed gamma-ray emission detected from the pulsar.

Abstract

We report about very high energy (VHE) gamma-ray observations of the Crab Nebula with the MAGIC telescope. The gamma-ray flux from the nebula was measured between 60 GeV and 9 TeV. The energy spectrum can be described with a curved power law dF/dE=f_0 (E/300GeV)^(a+b log10(E/300GeV)) with a flux normalization f_0 of (6.0+-0.2stat)*10^-10 cm^-2 s^-1 TeV^-1, a=-2.31+-0.06stat and b=-0.26+-0.07stat. The position of the IC-peak is determined at 77+-47 GeV. Within the observation time and the experimental resolution of the telescope, the gamma-ray emission is steady and pointlike. The emission's center of gravity coincides with the position of the pulsar. Pulsed gamma-ray emission from the pulsar could not be detected. We constrain the cutoff energy of the spectrum to be less than ~30 GeV, assuming that the differential energy spectrum has an exponential cutoff. For a super-exponential shape, the cutoff energy can be as high as ~60GeV.