Catherine Merck

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We report about very high energy (VHE) γ-ray observations of the Crab Nebula with the MAGIC telescope. The γ-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/300 GeV) (a+b log 10 (E/300 GeV)) with a flux normalization f 0 of (6.0 ± 0.2 stat) × 10 −10 cm −2 s −1 TeV −1(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)
All but three (M87, BL Lac and 3C 279) extragalactic sources detected so far at very high energy (VHE) γ-rays belong to the class of high-frequency peaked BL Lac (HBL) objects. This suggested to us a systematic scan of candidate sources with the MAGIC telescope, based on the compilation of X-ray blazars by Donato et al. (2001). The observations took place(More)
The MAGIC collaboration has observed very high energy gamma ray emission from the AGN 1ES 2344+514. A gamma-ray signal corresponding to an 11σ excess and an integral flux of (2.38 ± 0.30 stat ± 0.70 syst) × 10 −11 cm −2 s −1 above 200 GeV has been obtained from 23.1 hours of data taking between 2005 August 3 and 2006 January 1. The data confirm the(More)
We report on the results from the observations in very high energy band (VHE, E γ ≥ 100 GeV) of the black hole X-ray binary (BHXB) Cygnus X-1. The observations were performed with the MAGIC telescope, for a total of 40 hours during 26 nights, spanning the period between June and November 2006. Searches for steady γ-ray signals yielded no positive result and(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)
Studies using semantic priming paradigms to measure the integrity of the features underlying concepts in semantic dementia (SD) reported differential impairment, in that functional features appeared to be more robust to brain damage than other features, such as perceptual ones. However, these prior studies were single case reports and the inclusion of too(More)
The MAGIC collaboration observed BL Lacertae for 22. The source is the historical prototype and eponym of a class of low-frequency peaked BL Lacertae (LBL) objects. A very high energy (VHE) γ-ray signal was discovered with a 5.1 σ excess in the 2005 data. Above 200 GeV, an integral flux of (0.6 ± 0.2) × 10 −11 cm −2 s −1 was measured, corresponding to(More)
During its first data cycle, between 2005 and the beginning of year 2006, the fast repositioning system of the MAGIC Telescope allowed the observation of nine different GRBs as possible sources of Very High Energy (VHE) γ-rays. These observations were triggered by alerts from Swift, HETE-II, and Integral; they started as fast as possible after the alerts(More)