RT Journal Article
T1 Constraints on particle acceleration in SS433/W50 from MAGIC and HESS observations
A1 Barrio Uña, Juan Abel
A1 Bonnefoy, Simon Francois Albert
A1 Contreras González, José Luis
A1 Domínguez-Adame Acosta, Francisco
A1 Fidalgo Carreto, David
A1 Fonseca González, Mª Victoria
A1 López Moya, Marcos
A1 Nievas Rosillo, Mireia
AB Spontaneous breaking of Lorentz symmetry at energies on the order of the Planck energy or lower is predicted by many quantum gravity theories, implying non-trivial dispersion relations for the photon in vacuum. Consequently, gamma-rays of different energies, emitted simultaneously from astrophysical sources, could accumulate measurable differences in their time of flight until they reach the Earth. Such tests have been carried out in the past using fast variations of gamma-ray flux from pulsars, and more recently from active galactic nuclei and gamma-ray bursts. We present new constraints studying the gamma-ray emission of the galactic Crab Pulsar, recently observed up to TeV energies by the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) collaboration. A profile likelihood analysis of pulsar events reconstructed for energies above 400 GeV finds no significant variation in arrival time as their energy increases. Ninety-five percent CL limits are obtained on the effective Lorentz invariance violating energy scale at the level of EQG₁ > 5.5 x 10¹⁷ Ge V (4.5 10¹⁷ Ge V) for a linear, and E(QG₂) > 5.9 x 10¹⁰ Ge V (5.3 10¹⁰ Ge V) for a quadratic scenario, for the subluminal and the superluminal cases, respectively. A substantial part of this study is dedicated to calibration of the test statistic, with respect to bias and coverage properties. Moreover, the limits take into account systematic uncertainties, which are found to worsen the statistical limits by about 36%–42%. Our constraints would have been much more stringent if the intrinsic pulse shape of the pulsar between 200 GeV and 400 GeV was understood in sufficient detail and allowed inclusion of events well below 400 GeV.
PB EDP Sciencies
SN 1432-0746
YR 2018
FD 2018-04-09
LK https://hdl.handle.net/20.500.14352/12139
UL https://hdl.handle.net/20.500.14352/12139
LA eng
NO © EDP Sciencies.We would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2015-69818-P,  PA2012-36668, FPA2015-68378-P, FPA2015-69210-C6-2-R, FPA2015-69210-C6-4-R, FPA2015-69210-C6-6-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2015-71662-C2-2-P, CSD2009- 00064), and the Japanese JSPS and MEXT is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia “Severo Ochoa” SEV-2012-0234 and SEV-2015-0548, and Unidad de Excelencia “María de Maeztu” MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project 09/176, the University of Rijeka Project 13.12.1.3.02, the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, and by the Polish MNiSzW grant 2016/22/M/ ST9/00382.Artículo firmado por más de diez autores.
NO Ministerio de Economía y Competitividad (MINECO)
NO Centro de Excelencia "Severo Ochoa"
NO Unidad de Excelencia "Maria de Maeztu"
NO German B.M.B.F.
NO German M.P.G.
NO Italian INFN
NO Italian INAF
NO Swiss National Fund SNF
NO Croatian Science Foundation (HrZZ) Project
NO University of Rijeka Project
NO DFG Collaborative Research Centers
NO Polish MNiSzW grant
NO German Ministry for Education and Research (BMBF)
NO Max Planck Society
NO German Research Foundation (DFG)
NO French Ministry for Research
NO CNRS-IN2P3
NO Astroparticle Interdisciplinary Programme of the CNRS
NO UK Science and Technology Facilities Council (STFC)
NO IPNP of the Charles University
NO Czech Science Foundation
NO Polish Ministry of Science and Higher Education
NO South African Department of Science and Technology
NO National Research Foundation
DS Docta Complutense
RD 6 may 2024