MAGIC detection of Geminga: an Inverse Compton tail?

We report the detection of pulsed emission from the Geminga pulsar (PSR J0633+1746) with the MAGIC telescopes. After the Crab and Vela pulsars, Geminga is the third pulsar detected in the very-high-energy domain, and its estimated age of 340 ky makes it the oldest one. The spectrum derived by MAGIC extends from 15 GeV to 75 GeV and can be modeled by a power-law function with spectral index Γ = 5.62 ± 0.54. Joint fits to MAGIC and Fermi-LAT data disfavour the existence of a sub-exponential cut-off in this energy range. Our results are discussed in the framework of the outer gap pulsar model. The measured power-law emission can be interpreted as the transition from curvature radiation to inverse Compton (IC) scattering of charges accelerated in the northern outer gap. The IC component is expected to continue towards higher energies. These results have been published in Acciari et al. 2020 [1].