Oriana Mansutti

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We study the capability of the MAGIC telescope to observe under moderate 3 moonlight. TeV γ-ray signals from the Crab nebula were detected with the MAGIC telescope during periods when the Moon was above the horizon and during twilight. This was accomplished by increasing the trigger discriminator thresholds. No change is necessary in the high voltage(More)
Until April 2007 the MAGIC telescope used a 300 MSamples/s FADC system to sample the shaped PMT signals produced by the captured Cherenkov photons of air showers. Different algorithms to reconstruct the signal from the read-out samples (extractors) have been developed and are described and compared. Criteria based on the obtained charge and time(More)
We report on the discovery of Very High Energy (VHE) γ-ray emission from the BL Lacertae object 1ES 1011+496. The observation was triggered by an optical outburst in March 2007 and the source was observed with the MAGIC telescope from March to May 2007. Observing for 18.7 hr, we find an excess of 6.2 σ with an integrated flux above 200 GeV of (1.58±0.32) ·(More)
Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur(More)
The paper describes the different methods, used in the MAGIC experiment, to unfold experimental energy distributions of cosmic ray particles (grays). Questions and problems related to the unfolding are discussed. Various procedures are proposed which can help to make the unfolding robust and reliable. The different methods and procedures are implemented in(More)
Axion-Like Particles (ALPs) are predicted by many extensions of the Standard Model and give rise to characteristic dimming and polarization effects in a light beam travelling in a magnetic field. In this Letter, we demonstrate that photon-ALP mixing in cosmic magnetic fields produces an observable distortion in the energy spectra of distant gamma-ray(More)
The MAGIC telescope uses a 300 MHz FADC system to sample the shaped PMT signals produced by the captured Cherenkov photons of air showers. Different algorithms to reconstruct the signal from the read-out samples (extractors) have been developed and are described and compared. Criteria based on the obtained charge and time resolution/bias are defined and(More)
The MAGIC telescope has observed very high energy gamma-ray emission from the distant BL Lac object PG 1553+113 in 2005 and 2006. The overall significance is 8.8 σ in 18.8 h. The light curve shows no significant flux variations on a daily timescale , the flux level during 2005 was, however, significantly higher compared to 2006. The differential energy(More)
Photon propagation and the VHE γ-ray spectra of blazars: how transparent is really the Universe? ABSTRACT Recent findings by γ-ray Cherenkov telescopes suggest a higher transparency of the Universe to very-high-energy (VHE) photons than expected from current models of the Extragalactic Background Light. It has been shown that such transparency can be(More)