Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data

Abdollahi S, Ackermann M, Ajello M, Albert A, Atwood WB, Baldini L, Barbiellini G, Bellazzini R, Bissaldi E, Bloom ED, Bonino R, Bottacini E, Brandt TJ, Bruel P, Buson S, Caragiulo M, Cavazzuti E, Chekhtman A, Ciprini S, Costanza F, Cuoco A, Cutini S, D'Ammando F, De Palma F, Desiante R, Digel SW, Di Lalla N, Di Mauro M, Di Venere L, Donaggio B, Drell PS, Favuzzi C, Focke WB, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Green D, Guiriec S, Harding AK, Jogler T, Johannesson G, Kamae T, Kuss M, Larsson S, Latronico L, Li J, Longo F, Loparco F, Lubrano P, Magill JD, Malyshev D, Manfreda A, Mazziotta MN, Meehan M, Michelson PF, Mitthumsiri W, Mizuno T, Moiseev AA, Monzani ME, Morselli A, Negro M, Nuss E, Ohsugi T, Omodei N, Paneque D, Perkins JS, Pesce-Rollins M, Piron F, Pivato G, Principe G, Raino S, Rando R, Razzano M, Reimer A, Reimer O, Sgro C, Simone D, Siskind EJ, Spada F, Spandre G, Spinelli P, Strong AW, Tajima H, Thayer JB, Torres DF, Troja E, Vandenbroucke J, Zaharijas G, Zimmer S (2017)

Publication Type: Journal article

Publication year: 2017

Journal

Book Volume: 118

Journal Issue: 9

DOI: 10.1103/PhysRevLett.118.091103

Abstract

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10(-3). We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. The present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Authors with CRIS profile

Involved external institutions

National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) Italy (IT) University of Pisa / Università di Pisa (UniPi) Italy (IT) Italian Space Agency / Agenzia Spaziale Italiana (ASI) Italy (IT) University of California Santa Cruz United States (USA) (US) University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro Italy (IT) Los Alamos National Laboratory United States (USA) (US) Stanford University United States (USA) (US) Hiroshima University Japan (JP) Deutsches Elektronen-Synchrotron DESY Germany (DE) University of Geneva / Université de Genève (UNIGE) Switzerland (CH) National Aeronautics and Space Administration (NASA) United States (USA) (US) Max-Planck-Institut für extraterrestrische Physik (MPE) / Max Planck Institute for Extraterrestrial Physics Germany (DE) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) Spain (ES) University of Wisconsin - Madison United States (USA) (US) University of Montpellier / Université Montpellier France (FR) Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) Sweden (SE) NYCB Real-Time Computing, Inc. United States (USA) (US) University of Tokyo Japan (JP) Max-Planck-Institut für Physik (Werner-Heisenberg-Institut, MPP) / Max Planck Institute for Physics Germany (DE) University of Iceland (UI) / Háskóli Íslands Iceland (IS) Mahidol University / มหาวิทยาลัยมหิดล Thailand (TH) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) Italy (IT) Clemson University United States (USA) (US) University of Maryland United States (USA) (US) École Polytechnique - Université Paris-Saclay France (FR) George Mason University United States (USA) (US)

How to cite

APA:

Abdollahi, S., Ackermann, M., Ajello, M., Albert, A., Atwood, W.B., Baldini, L.,... Zimmer, S. (2017). Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data. Physical Review Letters, 118(9). https://dx.doi.org/10.1103/PhysRevLett.118.091103

MLA:

Abdollahi, S., et al. "Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data." Physical Review Letters 118.9 (2017).

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