Bibcode
MAGIC Collaboration; Albert, J.; Aliu, E.; Anderhub, H.; Antonelli, L. A.; Antoranz, P.; Backes, M.; Baixeras, C.; Barrio, J. A.; Bartko, H.; Bastieri, D.; Becker, J. K.; Bednarek, W.; Berger, K.; Bernardini, E.; Bigongiari, C.; Biland, A.; Bock, R. K.; Bonnoli, G.; Bordas, P.; Bosch-Ramon, V.; Bretz, T.; Britvitch, I.; Camara, M.; Carmona, E.; Chilingarian, A.; Commichau, S.; Contreras, J. L.; Cortina, J.; Costado, M. T.; Covino, S.; Curtef, V.; Dazzi, F.; de Angelis, A.; de Cea Del Pozo, E.; Delgado Mendez, C.; de Los Reyes, R.; de Lotto, B.; de Maria, M.; de Sabata, F.; Dominguez, A.; Dorner, D.; Doro, M.; Errando, M.; Fagiolini, M.; Ferenc, D.; Fernández, E.; Firpo, R.; Fonseca, M. V.; Font, L.; Galante, N.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Goebel, F.; Hayashida, M.; Herrero, A.; Höhne, D.; Hose, J.; Hsu, C. C.; Huber, S.; Jogler, T.; Kranich, D.; La Barbera, A.; Laille, A.; Leonardo, E.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Lorenz, E.; Majumdar, P.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Meyer, M.; Miranda, J. M.; Mirzoyan, R.; Moles, M.; Moralejo, A.; Nieto, D.; Nilsson, K.; Ninkovic, J.; Otte, N.; Oya, I.; Panniello, M.; Paoletti, R.; Paredes, J. M.; Pasanen, M.; Pascoli, D.; Pauss, F.; Pegna, R. G.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L. et al.
Bibliographical reference
Physics Letters B, Volume 668, Issue 4, p. 253-257.
Advertised on:
10
2008
Citations
231
Refereed citations
168
Description
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,
n=1,2. Parametrizing the delay between γ-rays of different
energies as Δt=±τE or
Δt=±τE, we find
τ=(0.030±0.012) s/GeV at the 2.5-σ level,
and τ=(3.71±2.57)×10
s/GeV, respectively. We use these results to establish lower
limits M>0.21×10 GeV and
M>0.26×10 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.
Related projects
Particle Astrophysics
The MAGIC Collaboration is integrated by 20 research institutes and university departments from Armenia, Bulgaria, Finland, Germany, Italy, Poland, Spain, Switzerland and USA. The collaboration comprises two 17m diameter telescopes, located at the Roque de los Muchachos Observatory, designed to measure the Cherenkov radiation associated with
Ramón
García López