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

M. Ackermann; M. Ajello; A. Allafort; W. B. Atwood; M. Axelsson; L. Baldini; G. Barbiellini; D. Bastieri; K. Bechtol; R. Bellazzini; B. Berenji; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; J. Bregeon; A. Brez; M. Brigida; P. Bruel; R. Buehler; S. Buson; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; C. Cecchi; E. Charles; A. Chekhtman; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; S. Cutini; F. De Palma; C. D. Dermer; S. W. Digel; E. Do Couto E Silva; P. S. Drell; A. Drlica-Wagner; R. Dubois; T. Enoto; L. Falletti; C. Favuzzi; S. J. Fegan; W. B. Focke; P. Fortin; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; N. Gehrels; S. Germani; N. Giglietto; F. Giordano; M. Giroletti; T. Glanzman; G. Godfrey; I. A. Grenier; J. E. Grove; S. Guiriec; D. Hadasch; M. Hayashida; E. Hays; R. E. Hughes; G. Jóhannesson; A. S. Johnson; T. J. Johnson; T. Kamae; H. Katagiri; J. Kataoka; J. Knödlseder; M. Kuss; J. Lande; L. Latronico; S. H. Lee; F. Longo; F. Loparco; M. N. Lovellette; P. Lubrano; G. M. Madejski; M. N. Mazziotta; J. E. McEnery; P. F. Michelson; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; T. Nakamori; M. Naumann-Godo; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; A. Okumura; N. Omodei; E. Orlando; J. F. Ormes; M. Ozaki; D. Paneque; J. H. Panetta; D. Parent; M. Pesce-Rollins; M. Pierbattista; F. Piron; S. Rain; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; S. Ritz; L. S. Rochester; C. Sgr; E. J. Siskind; P. D. Smith; G. Spandre; P. Spinelli; D. J. Suson; H. Takahashi; T. Tanaka; J. G. Thayer; J. B. Thayer; D. J. Thompson; L. Tibaldo; G. Tosti; E. Troja; T. L. Usher; J. Vandenbroucke; V. Vasileiou; G. Vianello; N. Vilchez; V. Vitale; A. P. Waite; P. Wang; B. L. Winer; K. S. Wood; Z. Yang; S. Zimmer

doi:10.1016/j.astropartphys.2011.10.007

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

M. Ackermann, M. Ajello, A. Allafort, W. B. Atwood, M. Axelsson, L. Baldini, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, E. D. Bloom, E. Bonamente, A. W. Borgland, A. Bouvier, J. Bregeon, A. Brez, M. Brigida, P. Bruel, R. BuehlerS. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, J. M. Casandjian, C. Cecchi, E. Charles, A. Chekhtman, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, S. Cutini, F. De Palma, C. D. Dermer, S. W. Digel, E. Do Couto E Silva, P. S. Drell, A. Drlica-Wagner, R. Dubois, T. Enoto, L. Falletti, C. Favuzzi, S. J. Fegan, W. B. Focke, P. Fortin, Y. Fukazawa, S. Funk, P. Fusco, F. Gargano, N. Gehrels, S. Germani, N. Giglietto, F. Giordano, M. Giroletti, T. Glanzman, G. Godfrey, I. A. Grenier, J. E. Grove, S. Guiriec, D. Hadasch, M. Hayashida, E. Hays, R. E. Hughes, G. Jóhannesson, A. S. Johnson, T. J. Johnson, T. Kamae, H. Katagiri, J. Kataoka, J. Knödlseder, M. Kuss, J. Lande, L. Latronico, S. H. Lee, F. Longo, F. Loparco, M. N. Lovellette, P. Lubrano, G. M. Madejski, M. N. Mazziotta, J. E. McEnery, P. F. Michelson, T. Mizuno, A. A. Moiseev, C. Monte, M. E. Monzani, A. Morselli, I. V. Moskalenko, S. Murgia, T. Nakamori, M. Naumann-Godo, P. L. Nolan, J. P. Norris, E. Nuss, T. Ohsugi, A. Okumura, N. Omodei, E. Orlando, J. F. Ormes, M. Ozaki, D. Paneque, J. H. Panetta, D. Parent, M. Pesce-Rollins^*, M. Pierbattista, F. Piron, S. Rain, R. Rando, M. Razzano, A. Reimer, O. Reimer, T. Reposeur, S. Ritz, L. S. Rochester, C. Sgr, E. J. Siskind, P. D. Smith, G. Spandre, P. Spinelli, D. J. Suson, H. Takahashi, T. Tanaka, J. G. Thayer, J. B. Thayer, D. J. Thompson, L. Tibaldo, G. Tosti, E. Troja, T. L. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, N. Vilchez, V. Vitale, A. P. Waite, P. Wang, B. L. Winer, K. S. Wood, Z. Yang, S. Zimmer

^*Corresponding author for this work

School of Advanced Science and Engineering

Research output: Contribution to journal › Article › peer-review

36 Citations (Scopus)

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 ∼6 and ∼13 GeV with an estimated uncertainty of ∼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.

Original language	English
Pages (from-to)	346-353
Number of pages	8
Journal	Astroparticle Physics
Volume	35
Issue number	6
DOIs	https://doi.org/10.1016/j.astropartphys.2011.10.007
Publication status	Published - 2012 Jan

Keywords

Absolute energy scale
Cosmic-rays
Fermi Large Area Telescope
Geomagnetic cutoff

ASJC Scopus subject areas

Astronomy and Astrophysics

Access to Document

10.1016/j.astropartphys.2011.10.007

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Ackermann, M., Ajello, M., Allafort, A., Atwood, W. B., Axelsson, M., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., ... 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

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, Jóhannesson, G, Johnson, AS, Johnson, TJ, Kamae, T, Katagiri, H, Kataoka, J, Knödlseder, J, Kuss, M, 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, Rain, S, Rando, R, Razzano, M, Reimer, A, Reimer, O, Reposeur, T, Ritz, S, Rochester, LS, Sgr, C, Siskind, EJ, Smith, PD, Spandre, G, Spinelli, P, Suson, DJ, Takahashi, H, 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, 'In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope', Astroparticle Physics, vol. 35, no. 6, pp. 346-353. https://doi.org/10.1016/j.astropartphys.2011.10.007

@article{8e91be1c2f4f414bbc96403a7bdabbb5,

title = "In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope",

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 ∼6 and ∼13 GeV with an estimated uncertainty of ∼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.",

keywords = "Absolute energy scale, Cosmic-rays, Fermi Large Area Telescope, Geomagnetic cutoff",

author = "M. Ackermann and M. Ajello and A. Allafort and Atwood, {W. B.} and M. Axelsson and L. Baldini and G. Barbiellini and D. Bastieri and K. Bechtol and R. Bellazzini and B. Berenji and Bloom, {E. D.} and E. Bonamente and Borgland, {A. W.} and A. Bouvier and J. Bregeon and A. Brez and M. Brigida and P. Bruel and R. Buehler and S. Buson and Caliandro, {G. A.} and Cameron, {R. A.} and Caraveo, {P. A.} and Casandjian, {J. M.} and C. Cecchi and E. Charles and A. Chekhtman and J. Chiang and S. Ciprini and R. Claus and J. Cohen-Tanugi and S. Cutini and {De Palma}, F. and Dermer, {C. D.} and Digel, {S. W.} and {Do Couto E Silva}, E. and Drell, {P. S.} and A. Drlica-Wagner and R. Dubois and T. Enoto and L. Falletti and C. Favuzzi and Fegan, {S. J.} and Focke, {W. B.} and P. Fortin and Y. Fukazawa and S. Funk and P. Fusco and F. Gargano and N. Gehrels and S. Germani and N. Giglietto and F. Giordano and M. Giroletti and T. Glanzman and G. Godfrey and Grenier, {I. A.} and Grove, {J. E.} and S. Guiriec and D. Hadasch and M. Hayashida and E. Hays and Hughes, {R. E.} and G. J{\'o}hannesson and Johnson, {A. S.} and Johnson, {T. J.} and T. Kamae and H. Katagiri and J. Kataoka and J. Kn{\"o}dlseder and M. Kuss and J. Lande and L. Latronico and Lee, {S. H.} and F. Longo and F. Loparco and Lovellette, {M. N.} and P. Lubrano and Madejski, {G. M.} and Mazziotta, {M. N.} and McEnery, {J. E.} and Michelson, {P. F.} and T. Mizuno and Moiseev, {A. A.} and C. Monte and Monzani, {M. E.} and A. Morselli and Moskalenko, {I. V.} and S. Murgia and T. Nakamori and M. Naumann-Godo and Nolan, {P. L.} and Norris, {J. P.} and E. Nuss and T. Ohsugi and A. Okumura and N. Omodei and E. Orlando and Ormes, {J. F.} and M. Ozaki and D. Paneque and Panetta, {J. H.} and D. Parent and M. Pesce-Rollins and M. Pierbattista and F. Piron and S. Rain and R. Rando and M. Razzano and A. Reimer and O. Reimer and T. Reposeur and S. Ritz and Rochester, {L. S.} and C. Sgr and Siskind, {E. J.} and Smith, {P. D.} and G. Spandre and P. Spinelli and Suson, {D. J.} and H. Takahashi and T. Tanaka and Thayer, {J. G.} and Thayer, {J. B.} and Thompson, {D. J.} and L. Tibaldo and G. Tosti and E. Troja and Usher, {T. L.} and J. Vandenbroucke and V. Vasileiou and G. Vianello and N. Vilchez and V. Vitale and Waite, {A. P.} and P. Wang and Winer, {B. L.} and Wood, {K. S.} and Z. Yang and S. Zimmer",

note = "Funding Information: The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the USA , the Commissariat {\`a} l{\textquoteright}Energie Atomique and the Centre National de la Recherche Scientifique/ Institut National de Physique Nucl{\'e}aire et de Physique des Particules in France , the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy , the Ministry of Education, Culture, Sports, Science and Technology (MEXT) , High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan , and the K.A. Wallenberg Foundation , the Swedish Research Council and the Swedish National Space Board in Sweden . ",

year = "2012",

month = jan,

doi = "10.1016/j.astropartphys.2011.10.007",

language = "English",

volume = "35",

pages = "346--353",

journal = "Astroparticle Physics",

issn = "0927-6505",

publisher = "Elsevier",

number = "6",

}

TY - JOUR

T1 - In-flight measurement of the absolute energy scale of the Fermi Large Area Telescope

AU - Ackermann, M.

AU - Ajello, M.

AU - Allafort, A.

AU - Atwood, W. B.

AU - Axelsson, M.

AU - Baldini, L.

AU - Barbiellini, G.

AU - Bastieri, D.

AU - Bechtol, K.

AU - Bellazzini, R.

AU - Berenji, B.

AU - Bloom, E. D.

AU - Bonamente, E.

AU - Borgland, A. W.

AU - Bouvier, A.

AU - Bregeon, J.

AU - Brez, A.

AU - Brigida, M.

AU - Bruel, P.

AU - Buehler, R.

AU - Buson, S.

AU - Caliandro, G. A.

AU - Cameron, R. A.

AU - Caraveo, P. A.

AU - Casandjian, J. M.

AU - Cecchi, C.

AU - Charles, E.

AU - Chekhtman, A.

AU - Chiang, J.

AU - Ciprini, S.

AU - Claus, R.

AU - Cohen-Tanugi, J.

AU - Cutini, S.

AU - De Palma, F.

AU - Dermer, C. D.

AU - Digel, S. W.

AU - Do Couto E Silva, E.

AU - Drell, P. S.

AU - Drlica-Wagner, A.

AU - Dubois, R.

AU - Enoto, T.

AU - Falletti, L.

AU - Favuzzi, C.

AU - Fegan, S. J.

AU - Focke, W. B.

AU - Fortin, P.

AU - Fukazawa, Y.

AU - Funk, S.

AU - Fusco, P.

AU - Gargano, F.

AU - Gehrels, N.

AU - Germani, S.

AU - Giglietto, N.

AU - Giordano, F.

AU - Giroletti, M.

AU - Glanzman, T.

AU - Godfrey, G.

AU - Grenier, I. A.

AU - Grove, J. E.

AU - Guiriec, S.

AU - Hadasch, D.

AU - Hayashida, M.

AU - Hays, E.

AU - Hughes, R. E.

AU - Jóhannesson, G.

AU - Johnson, A. S.

AU - Johnson, T. J.

AU - Kamae, T.

AU - Katagiri, H.

AU - Kataoka, J.

AU - Knödlseder, J.

AU - Kuss, M.

AU - Lande, J.

AU - Latronico, L.

AU - Lee, S. H.

AU - Longo, F.

AU - Loparco, F.

AU - Lovellette, M. N.

AU - Lubrano, P.

AU - Madejski, G. M.

AU - Mazziotta, M. N.

AU - McEnery, J. E.

AU - Michelson, P. F.

AU - Mizuno, T.

AU - Moiseev, A. A.

AU - Monte, C.

AU - Monzani, M. E.

AU - Morselli, A.

AU - Moskalenko, I. V.

AU - Murgia, S.

AU - Nakamori, T.

AU - Naumann-Godo, M.

AU - Nolan, P. L.

AU - Norris, J. P.

AU - Nuss, E.

AU - Ohsugi, T.

AU - Okumura, A.

AU - Omodei, N.

AU - Orlando, E.

AU - Ormes, J. F.

AU - Ozaki, M.

AU - Paneque, D.

AU - Panetta, J. H.

AU - Parent, D.

AU - Pesce-Rollins, M.

AU - Pierbattista, M.

AU - Piron, F.

AU - Rain, S.

AU - Rando, R.

AU - Razzano, M.

AU - Reimer, A.

AU - Reimer, O.

AU - Reposeur, T.

AU - Ritz, S.

AU - Rochester, L. S.

AU - Sgr, C.

AU - Siskind, E. J.

AU - Smith, P. D.

AU - Spandre, G.

AU - Spinelli, P.

AU - Suson, D. J.

AU - Takahashi, H.

AU - Tanaka, T.

AU - Thayer, J. G.

AU - Thayer, J. B.

AU - Thompson, D. J.

AU - Tibaldo, L.

AU - Tosti, G.

AU - Troja, E.

AU - Usher, T. L.

AU - Vandenbroucke, J.

AU - Vasileiou, V.

AU - Vianello, G.

AU - Vilchez, N.

AU - Vitale, V.

AU - Waite, A. P.

AU - Wang, P.

AU - Winer, B. L.

AU - Wood, K. S.

AU - Yang, Z.

AU - Zimmer, S.

N1 - Funding Information: The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the USA , the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique/ Institut National de Physique Nucléaire et de Physique des Particules in France , the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy , the Ministry of Education, Culture, Sports, Science and Technology (MEXT) , High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan , and the K.A. Wallenberg Foundation , the Swedish Research Council and the Swedish National Space Board in Sweden .

PY - 2012/1

Y1 - 2012/1

N2 - 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 ∼6 and ∼13 GeV with an estimated uncertainty of ∼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.

AB - 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 ∼6 and ∼13 GeV with an estimated uncertainty of ∼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.

KW - Absolute energy scale

KW - Cosmic-rays

KW - Fermi Large Area Telescope

KW - Geomagnetic cutoff

UR - http://www.scopus.com/inward/record.url?scp=81455161628&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=81455161628&partnerID=8YFLogxK

U2 - 10.1016/j.astropartphys.2011.10.007

DO - 10.1016/j.astropartphys.2011.10.007

M3 - Article

AN - SCOPUS:81455161628

SN - 0927-6505

VL - 35

SP - 346

EP - 353

JO - Astroparticle Physics

JF - Astroparticle Physics

IS - 6

ER -

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

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