In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope

Ackermann M, Ajello M, Allafort A, Atwood WB, Axelsson M, Baldini L, Barbiellini G, Bastieri D, Bechtol K, Bellazzini R, Berenji B, Bloom ED, Bonamente E, Borgland AW, Bouvier A, Bregeon J, Brez A, Brigida M, Bruel P, Buehler R, Buson S, Caliandro GA, Cameron RA, Caraveo PA, Casandjian JM, Cecchi C, Charles E, Chekhtman A, Chiang J, Ciprini S, Claus R, Cohen-Tanugi J, Cutini S, De Palma F, Dermer CD, Digel SW, Do Couto E Silva E, Drell PS, Drlica-Wagner A, Dubois R, Enoto T, Falletti L, Favuzzi C, Fegan SJ, Focke WB, Fortin P, Fukazawa Y, Funk S, Fusco P, Gargano F, Gehrels N, Germani S, Giglietto N, Giordano F, Giroletti M, Glanzman T, Godfrey G, Grenier IA, Grove JE, Guiriec S, Hadasch D, Hayashida M, Hays E, Hughes RE, Johannesson G, Johnson AS, Johnson TJ, Kamae T, Katagiri H, Kataoka J, Knoedlseder J, Kuss MW, Lande J, Latronico L, Lee SH, Longo F, Loparco F, Lovellette MN, Lubrano P, Madejski GM, Mazziotta MN, Mcenery JE, Michelson PF, Mizuno T, Moiseev AA, Monte C, Monzani ME, Morselli A, Moskalenko IV, Murgia S, Nakamori T, Naumann-Godo M, Nolan PL, Norris JP, Nuss E, Ohsugi T, Okumura A, Omodei N, Orlando E, Ormes JF, Ozaki M, Paneque D, Panetta JH, Parent D, Pesce-Rollins M, Pierbattista M, Piron F, Raino S, Rando R, Razzano M, Reimer A, Reimer O, Reposeur T, Ritz S, Rochester LS, Sgro C, Siskind EJ, Smith PD, Spandre G, Spinelli P, Suson DJ, Takahashi HH, Tanaka T, Thayer JG, Thayer JB, Thompson DJ, Tibaldo L, Tosti G, Troja E, Usher TL, Vandenbroucke J, Vasileiou V, Vianello G, Vilchez N, Vitale V, Waite AP, Wang P, Winer BL, Wood KS, Yang Z, Zimmer S (2012)

Publication Type: Journal article

Publication year: 2012

Journal

Book Volume: 35

Pages Range: 346-353

Journal Issue: 6

DOI: 10.1016/j.astropartphys.2011.10.007

Abstract

The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between similar to 6 and similar to 13 GeV with an estimated uncertainty of similar to 2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars. (C) 2011 Elsevier B.V. All rights reserved.

Authors with CRIS profile

Involved external institutions

National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) Italy (IT) Stanford University United States (USA) (US) University of California Santa Cruz United States (USA) (US) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) Spain (ES) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) Italy (IT) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot France (FR) Università degli Studi di Perugia Italy (IT) Stockholm University / Stockholms universitet Sweden (SE) University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro Italy (IT) École Polytechnique - Université Paris-Saclay France (FR) Artep United States (USA) (US) University of Montpellier / Université Montpellier France (FR) Italian Space Agency / Agenzia Spaziale Italiana (ASI) Italy (IT) University of Alabama in Huntsville (UAH) United States (USA) (US) National Center for Scientific Research / Centre national de la recherche scientifique (CNRS) France (FR) U.S. Naval Research Laboratory United States (USA) (US) Hiroshima University Japan (JP) Ohio State University United States (USA) (US) University of Iceland (UI) / Háskóli Íslands Iceland (IS) National Academy of Sciences United States (USA) (US) Ibaraki University / 茨城大学 Japan (JP) Waseda University / 早稲田大学 Japan (JP) Kyoto University / 京都大学 Kyōto daigaku Japan (JP) University of Maryland United States (USA) (US) University of Denver United States (USA) (US) Japan Aerospace eXploration Agency (JAXA) Japan (JP) George Mason University United States (USA) (US) Université Bordeaux 1, Sciences et Technologies France (FR) NYCB Real-Time Computing, Inc. United States (USA) (US) Purdue University Northwest / Purdue University Calumet United States (USA) (US) National Aeronautics and Space Administration (NASA) United States (USA) (US) AlbaNova University Centre / Kungliga Tekniska Högskolan AlbaNova Universitetscentrum Sweden (SE)

How to cite

APA:

Ackermann, M., Ajello, M., Allafort, A., Atwood, W.B., Axelsson, M., Baldini, L.,... Zimmer, S. (2012). In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope. Astroparticle Physics, 35(6), 346-353. https://doi.org/10.1016/j.astropartphys.2011.10.007

MLA:

Ackermann, Markus, et al. "In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope." Astroparticle Physics 35.6 (2012): 346-353.

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