Grid services for the MAGIC experiment

Exploring signals from the outer space has become an observational science under fast expansion. On the basis of its advanced technology the MAGIC telescope is the natural building block for the first large scale ground based high energy gamma-ray observatory. The low energy threshold for gamma-rays together with different background sources leads to a considerable amount of data. The analysis will be done in different institutes spread over Europe. Therefore MAGIC offers the opportunity to use the Grid technology to setup a distributed computational and data intensive analysis system with the nowadays available technology. Benefits of Grid computing for the MAGIC telescope are presented.Comment: 5 pages, 1 figures, to be published in the Proceedings of the 6th International Symposium ''Frontiers of Fundamental and Computational Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200

MAGIC observations of very high energy gamma-rays from HESS J1813-178

Recently, the HESS collaboration has reported the detection of gamma-ray emission above a few hundred GeV from eight new sources located close to the Galactic Plane. The source HESS J1813-178 has sparked particular interest, as subsequent radio observations imply an association with SNR G12.82-0.02. Triggered by the detection in VHE gamma-rays, a positionally coincident source has also been found in INTEGRAL and ASCA data. In this Letter we present MAGIC observations of HESS J1813-178, resulting in the detection of a differential gamma-ray flux consistent with a hard-slope power law, described as dN/(dA dt dE) = (3.3+/-0.5)*10^{-12} (E/TeV)^{-2.1+/-0.2} cm^(-2)s^(-1)TeV^(-1). We briefly discuss the observational technique used, the procedure implemented for the data analysis, and put this detection in the perspective of multifrequency observations.Comment: Accepted by ApJ Letter

Observation of VHE Gamma Radiation from HESS J1834-087/W41 with the MAGIC Telescope

Recently, the HESS array has reported the detection of gamma-ray emission above a few hundred GeV from eight new sources located close to the Galactic Plane. The source HESS J1834-087 is spatially coincident with SNR G23.3-0.3 (W41). Here we present MAGIC observations of this source, resulting in the detection of a differential gamma-ray flux consistent with a power law, described as dN/(dA dt dE) = (3.7 +/- 0.6)*10^(-12) (E/TeV)^(-2.5 +/- 0.2) \ cm^(-2)s^(-1)TeV^(-1). We confirm the extended character of this flux. We briefly discuss the observational technique used, the procedure implemented for the data analysis, and put this detection in the perspective of the molecular environment found in the region of W41. We present 13CO and 12CO emission maps showing the existence of a massive molecular cloud in spatial superposition with the MAGIC detection.Comment: Accepted by ApJ Letter

Variable Very High Energy Gamma-ray Emission from the Microquasar LS I +61 303

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and laboratories for elucidating the physics of relativistic jets. Here 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 at a similar orbital phase, suggesting the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or the absorption processes.Comment: 11 pages with 4 figure

Variable Very High Energy Gamma-ray Emission from the Microquasar LS I +61 303

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and laboratories for elucidating the physics of relativistic jets. Here 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 at a similar orbital phase, suggesting the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or the absorption processes.Comment: 11 pages with 4 figure

Observation of Gamma Rays from the Galactic Center with the MAGIC Telescope

Recently, the Galactic Center has been reported to be a source of very high energy (VHE) gamma-rays by the VERITAS, CANGAROO and HESS experiments. The energy spectra as measured by these experiments show substantial differences. In this Letter we present MAGIC observations of the Galactic Center, resulting in the detection of a differential gamma-ray flux consistent with a steady, hard-slope power law, described as dN/(dA dt dE) = (2.9+/-0.6)*10^{-12} (E/TeV)^{-2.2+/-0.2} cm^{-2}s^{-1}TeV^{-1}. The gamma-ray source is centered at (Ra, Dec)=(17h 45m 20s, -29deg 2'. This result confirms the previous measurements by the HESS experiment and indicates a steady source of TeV gamma-rays. We briefly describe the observational technique used, the procedure implemented for the data analysis, and discuss the results in the perspective of different models proposed for the acceleration of the VHE gamma-rays.Comment: ApJL submitte

Discovery of Very High Energy Gamma Rays from 1ES 1218+30.4

The MAGIC collaboration has studied the high-frequency-peaked BL Lac object 1ES 1218+30.4, at a redshift z=0.182, using the MAGIC imaging air Cerenkov telescope located on the Canary Island of La Palma. A gamma-ray signal was observed with 6.4 σ significance. The differential energy spectrum for an energy threshold of 120 GeV can be fitted by a simple power law, yielding FE(E)=(8.1+/-2.1)×10-7[E/(250 GeV)]-3.0+/-0.4 TeV-1 m-2 s-1. During the 6 days of observation in 2005 January, no time variability on timescales of days was found within the statistical errors. The observed integral flux above 350 GeV is nearly a factor of 2 below the upper limit reported by the Whipple collaboration in 2003

Flux upper limit on gamma-ray emission by GRB 050713a from magic telescope observations

The long-duration gamma-ray burst GRB 050713a was observed by the MAGIC Telescope 40 s after the burst onset and followed up for 37 minutes, until twilight. The observation, triggered by a Swift alert, covered energies above approximate to 175 GeV. Using standard MAGIC analysis, no evidence of a gamma-ray signal was found. As the redshift of the GRB was not measured directly, the flux upper limit estimated by MAGIC is still compatible with the assumption of an unbroken power-law spectrum extending from a few hundred keV to our energy range