Phase-resolved Crab pulsar measurements from 25 to 400 GeV with the MAGIC telescopes

TL;DR

This study presents phase-resolved measurements of the Crab pulsar from 25 to 400 GeV using MAGIC telescopes, revealing a hard spectral component that challenges standard curvature radiation models.

Contribution

It provides the first detailed phase-resolved energy spectra of the Crab pulsar at very high energies, showing a spectral extension beyond exponential cutoff.

Findings

Detection of two peaks in both observation modes

Identification of a hard spectral component up to 400 GeV

Evidence against curvature radiation dominance above 25 GeV

Abstract

We report on observations of the Crab pulsar with the MAGIC telescopes. Our data were taken in both monoscopic (> 25GeV) and stereoscopic (> 50GeV) observation modes. Two peaks were detected with both modes and phase-resolved energy spectra were calculated. By comparing with Fermi- LAT measurements, we find that the energy spectrum of the Crab pulsar does not follow a power law with an exponential cutoff, but has an additional hard component, extending up to at least 400 GeV. This suggests that the emission above 25 GeV is not dominated by curvature radiation, as suggested in the standard scenarios of the OG and SG models.