Probing quantum gravity using photons from a flare of the active galactic nucleus Markarian 501 observed by the MAGIC telescope
Abstract
We analyze the timing of photons observed by the MAGIC telescope during a flare of the active galactic nucleus Mkn 501 for a possible correlation with energy, as suggested by some models of quantum gravity (QG), which predict a vacuum refractive index ≃ 1 + (E / MQGn)n, n = 1, 2. Parametrizing the delay between γ-rays of different energies as Δ t = ± τl E or Δ t = ± τq E2, we find τl = (0.030 ± 0.012) s / GeV at the 2.5-σ level, and τq = (3.71 ± 2.57) × 10-6 s / GeV2, respectively. We use these results to establish lower limits MQG 1 > 0.21 × 1018 GeV and MQG 2 > 0.26 × 1011 GeV at the 95% C.L. Monte Carlo studies confirm the MAGIC sensitivity to propagation effects at these levels. Thermal plasma effects in the source are negligible, but we cannot exclude the importance of some other source effect. Show more
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https://doi.org/10.3929/ethz-b-000003105Publication status
publishedExternal links
Journal / series
Physics Letters BVolume
Pages / Article No.
Publisher
ElsevierSubject
Gamma-ray sources (Individual: Mkn 501); Active galactic nuclei; Quantum gravity; Supersymmetric models; Particle accelerationOrganisational unit
03381 - Pauss, Felicitas (emeritus)
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