Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC

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 gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 GeV. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 GeV, 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.Comment: Slight modification of the analysis: Fitting a more general function to the combined data set of COMPTEL, EGRET and MAGIC. Final result and conclusion is unchange

MAGIC upper limits on the VHE gamma-ray emission from the satellite galaxy Willman 1

We present the result of the observation of the ultra-faint dwarf galaxy Willman 1 performed with the 17 m MAGIC Cherenkov telescope during 15.5 hours between March and May 2008. No significant gamma-ray emission was found above 100 GeV. We derived upper limits of the order of $10^{-12}$ photons cm$^{-2}$ s$^{-1}$ on the integral flux above 100 GeV, which we compare with predictions from several of the established neutralino benchmark models in the mSUGRA parameter space. The neutralino annihilation spectra are defined after including the recently discovered contribution of internal bremsstrahlung from the virtual sparticles that mediate the annihilation. Flux boost factors of three orders of magnitude are required even in the most optimistic scenario to match our upper limits. However, uncertainties in the DM distribution (e.g., presence of substructure in the halo) may significantly reduce such boost estimates. Future observations will likely allow us to improve the derived upper limits probably by up to one order of magnitude so that - at least in some regions - the mSUGRA parameter space may be constrained

Pulsar observations with the MAGIC Telescope

Pulsars were detected by EGRET up to energies below 20 GeV. Observations at higher energies with ground based experiments so far failed to detect pulsars, indicating a sharp cutoff of the pulsedemission.Herewepresenttheresultsofthesearch for very high gamma-ray emission from the pulsar PSR B1951+32