Victor Stamatescu

Learn More
Context. We present the discovery of very high energy (VHE, E > 100 GeV) γ-ray emission from the BL Lac object 1ES 1215+303 by the MAGIC telescopes and simultaneous multi-wavelength data in a broad energy range from radio to γ-rays. Aims. We study the VHE γ-ray emission from 1ES 1215+303 and its relation to the emissions in other wavelengths. Methods.(More)
  • S Kabuki, R Enomoto, G V Bicknell, R W Clay, P G Edwards, S Gunji +42 others
  • 2008
We have observed the giant radio galaxy Centaurus A and the globular cluster ω Centauri in the TeV energy region using the CANGAROO-III stereoscopic system. The system has been in operation since 2004 with an array of four Imaging Atmospheric Cherenkov Telescopes (IACT) with ∼100-m spacings. The observations were carried out in March and April 2004. In(More)
  • T Nakamori, H Kubo, T Yoshida, T Tanimori, R Enomoto, G V Bicknell +43 others
  • 2008
We have observed the supernova remnant MSH 15−52 (G320.4−1.2), which contains the gamma-ray pulsar PSR B1509−58, using the CANGAROO-III imaging atmospheric Cherenkov telescope array from April to June in 2006. We detected gamma rays above 810 GeV at the 7 sigma level during a total effective exposure of 48.4 hours. We obtained a differential gamma-ray flux(More)
We report on the observation of γ-rays above 25 GeV from the Crab pulsar (PSR B0532+21) using the MAGIC I telescope. Two data sets from observations during the winter period 2007/2008 and 2008/2009 are used. In order to discuss the spectral shape from 100 MeV to 100 GeV, one year of public Fermi Large Area Telescope (Fermi-LAT) data are also analyzed to(More)
  • M Ohishi, M Mori, Y Adachi, A Asahara, G V Bicknell, R W Clay +54 others
In 2004, we searched for very high energy (VHE) gamma-ray emission from the Galactic Plane using the CANGAROO-III stereoscopic observation system. Two different longitude regions (= −19 • .5 and = +13 • .0) on the Galactic Plane were observed during July and August 2004. We analyzed events that triggered three telescopes aiming to measure the diffuse(More)
Context. On March 28, 2011, the BAT instrument on board the Swift satellite detected a new transient event that in the very beginning was classified as a gamma ray burst (GRB). However, the unusual X-ray flaring activity observed from a few hours up to days after the onset of the event made a different nature seem to be more likely. The long-lasting(More)
We report on the detection of very-high energy (VHE, E > 100 GeV) γ-ray emission from NGC 1275, the central radio galaxy of the Perseus cluster of galaxies. The source has been detected by the MAGIC telescopes with a statistical significance of 6.6 σ above 100 GeV in 46 hr of stereo observations carried out between August 2010 and February 2011. The(More)
  • R Enomoto, G V Bicknell, R W Clay, P G Edwards, S Gunji, S Hara +39 others
  • 2007
Optical images of SN 1987A show a triple ring structure. The inner (dust) ring has recently increased in brightness and in the number of hot spots suggesting that the supernova shock wave has collided with the dense pre-existing circumstellar medium, a scenario supported by radio and X-ray observations. Such a shocked environment is widely expected to(More)
  • Y Higashi, G V Bicknell, R W Clay, P G Edwards, R Enomoto, S Gunji +43 others
  • 2007
The H.E.S.S. collaboration has reported the detection of the gamma-ray emission from eight new sources located in the Galactic Plane. HESS J1804-216 is one of the brightest, and its size and photon index suggest it as one of the largest and softest sources. We observed HESS J1804-216 with CANGAROO-III telescopes from May to July in 2006. We detected(More)
  • R Kiuchi, M Mori, G Bicknell, R Clay, P Edwards, R Enomoto +44 others
More than forty gamma-ray sources have been detected by atmospheric Cherenkov telescopes at TeV energies. Although there are many theoretical predictions on the possible gamma-ray fluxes from these gigantic objects assuming various emission mechanisms, no cluster of galaxies have been proven to be a TeV gamma-ray emitter until now. We have observed a couple(More)