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Nyquist sinc-pulse shaping provides spectral efficiencies close to the theoretical limit. In this paper we discuss the analogy to optical orthogonal frequency division multiplexing and compare both techniques with respect to spectral efficiency and peak to average power ratio. We then show that using appropriate algorithms, Nyquist pulse shaped modulation(More)
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 giga-electron volts. In(More)
The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy(More)
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)
A search for a very-high-energy (VHE; ≥100  GeV) γ-ray signal from self-annihilating particle dark matter (DM) is performed towards a region of projected distance r∼45-150  pc from the Galactic center. The background-subtracted γ-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) γ-ray instrument in the energy range between 300 GeV(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)
PURPOSE The aim of this histochemical study was to demonstrate the absorption of dextran 500 and its distribution in the cornea after storage under standard eye bank conditions. Furthermore, an attempt was made to distinguish between the soluble and insoluble parts of dextran 500 absorbed by the cornea, in order to see how much dextran remains in the cornea(More)
BACKGROUND Perfluorocarbon liquids are established tools for intraoperative hydrokinetic retinal manipulation. Because of their high specific gravity, however, they may well cause mechanical damage to the retina when applied as a long-term vitreous substitute. Perfluorohexyloctane, a semi-fluorinated liquid fluorocarbon of low specific gravity (1.35 g/cm3),(More)
The purpose of this study was to obtain further information on the viability of organ-cultured human cornea. We thus used a specific staining method for succinate dehydrogenase (SDH), which is located in the membrane system of vital mitochondria. We examined fresh and long-term-cultured human corneas. After an initial incubation period in dextran-free(More)