RT Journal Article
T1 Probing quantum gravity using photons from a flare of the active galactic nucleus Markarian 501 observed by the MAGIC telescope
A1 Antoranz Canales, Pedro
A1 Barrio Uña, Juan Abel
A1 Contreras González, José Luis
A1 Fonseca González, María Victoria
A1 Miranda Pantoja, José Miguel
A1 Nieto Castaño, Daniel
AB 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 similar or equal to 1 + (E/M-QGn)(n), n = 1, 2. Parametrizing the delay between gamma-rays of different energies as Delta t = +/-tau E-1 or Delta t = +/-tau E-q(2), we find tau(1) = (0.030 +/- 0.012) s/GeV at the 2.5-sigma level, and tau(q) = (3.71 +/- 2.57) x 10(-6) s/GeV2, respectively. We use these results to establish lower limits M-QG1 > 0.21 X 10(18) GeV and M-QG2 > 0.26 x 10(11) 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. (C) 2008 Elsevier B.V. All rights reserved.
PB Elsevier Science BV
SN 0370-2693
YR 2008
FD 2008-10-16
LK https://hdl.handle.net/20.500.14352/50808
UL https://hdl.handle.net/20.500.14352/50808
LA eng
NO © Elsevier Science. The MAGIC Collaboration thanks the IAC for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma and gratefully acknowledges the support of the German BMBF and MPG, the Italian INFN and the Spanish CICYT. This work was also supported by ETH Research Grant TH 34/04 3 and the Polish MNiI Grant 1P03D01028. The work of J.E. and N.E.M. was partially supported by the European Union through the Marie Curie Research and Training Network UniverseNet MRTN-CT-2006-035863, and that of D.V.N. by DOE grant DE-FG02-95ER40917.
NO German BMBF
NO German MPG
NO Italian INFN
NO Spanish CICYT
NO ETH Research Grant TH
NO Polish MNiI
NO European Union through the Marie Curie Research and Training Network UniverseNet
NO DOE
DS Docta Complutense
RD 7 abr 2025