Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope

M. De Naurois; J. Holder; R. Bazer-Bachi; H. Bergeret; P. Bruel; A. Cordier; G. Debiais; J. P. Dezalay; D. Dumora; E. Durand; P. Eschstruth; P. Espigat; B. Fahre; P. Fleury; N. Hérault; M. Hrabovsky; S. Incerti; R. Le Gallou; F. Münz; A. Musquère; J. F. Olive; E. Paré; J. Québert; R. C. Rannot; T. Reposeur; L. Rob; P. Roy; T. Sako; P. Schovanek; D. A. Smith; P. Snabre; A. Volte

doi:10.1086/337991

Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope

M. De Naurois
, J. Holder
, R. Bazer-Bachi
, H. Bergeret
, P. Bruel
, A. Cordier
, G. Debiais
, J. P. Dezalay
, D. Dumora
, E. Durand
, P. Eschstruth
, P. Espigat
, B. Fahre
, P. Fleury
, N. Hérault
, M. Hrabovsky
, S. Incerti
, R. Le Gallou
, F. Münz
, A. Musquère

J. F. Olive, E. Paré, J. Québert, R. C. Rannot, T. Reposeur, L. Rob, P. Roy, T. Sako, P. Schovanek, D. A. Smith, P. Snabre, A. Volte

Universités Paris VI and VII
Laboratoire de l'Accélérateur Linéaire
University of Leeds
IRAP/CNRS
Université de Perpignan
UMR 5797
Collège de France
Palacky University Olomouc
Charles University
Bhabha Atomic Research Centre
Nagoya University
Inst. Sci. Genie des Mat. et Proc.

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

Abstract

We have converted the former solar electrical plant THEMIS (French Pyrenees) into an atmospheric Cerenkov detector called CELESTE, which records gamma rays above 30 GeV (7 × 10²⁴ Hz). Here we present the first sub-100 GeV detection by a ground-based telescope of a gamma-ray source, the Crab Nebula, in the energy region between satellite measurements and imaging atmospheric Cerenkov telescopes. At our analysis threshold energy of 60 ± 20 GeV we measure a gamma-ray rate of 6.1 ± 0.8 minute ^-1. Allowing for 30% systematic uncertainties and a 30% error on the energy scale yields an integral gamma-ray flux of I(E > 60GeV) = 6.2 _-2.3^+5.3 × 10^-6 photons m^-2 s^-1. The analysis methods used to obtain the gamma-ray signal from the raw data are detailed. In addition, we determine the upper limit for pulsed emission to be less than 12% of the Crab flux at the 99% confidence level, in the same energy range. Our result indicates that if the power law observed by EGRET is attenuated by a cutoff of form e^-E/E0, then E₀ < 26 GeV. This is the lowest energy probed by a Cerenkov detector and leaves only a narrow range unexplored beyond the energy range studied by EGRET.

Original language	English
Pages (from-to)	343-357
Number of pages	15
Journal	Astrophysical Journal
Volume	566
Issue number	1 I
DOIs	https://doi.org/10.1086/337991
Publication status	Published - 10 Feb 2002

Keywords

Gamma rays: observations
ISM: individual (Crab Nebula)
Pulsars: individual (Crab Pulsar)
Supernova remnants

Access to Document

10.1086/337991

Cite this

De Naurois, M., Holder, J., Bazer-Bachi, R., Bergeret, H., Bruel, P., Cordier, A., Debiais, G., Dezalay, J. P., Dumora, D., Durand, E., Eschstruth, P., Espigat, P., Fahre, B., Fleury, P., Hérault, N., Hrabovsky, M., Incerti, S., Le Gallou, R., Münz, F., ... Volte, A. (2002). Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope. Astrophysical Journal, 566(1 I), 343-357. https://doi.org/10.1086/337991

@article{5bc996c7f8fc4d84a7aac298feafba97,

title = "Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope",

abstract = "We have converted the former solar electrical plant THEMIS (French Pyrenees) into an atmospheric Cerenkov detector called CELESTE, which records gamma rays above 30 GeV (7 × 1024 Hz). Here we present the first sub-100 GeV detection by a ground-based telescope of a gamma-ray source, the Crab Nebula, in the energy region between satellite measurements and imaging atmospheric Cerenkov telescopes. At our analysis threshold energy of 60 ± 20 GeV we measure a gamma-ray rate of 6.1 ± 0.8 minute -1. Allowing for 30\% systematic uncertainties and a 30\% error on the energy scale yields an integral gamma-ray flux of I(E > 60GeV) = 6.2 -2.3+5.3 × 10-6 photons m-2 s-1. The analysis methods used to obtain the gamma-ray signal from the raw data are detailed. In addition, we determine the upper limit for pulsed emission to be less than 12\% of the Crab flux at the 99\% confidence level, in the same energy range. Our result indicates that if the power law observed by EGRET is attenuated by a cutoff of form e-E/E0, then E0 < 26 GeV. This is the lowest energy probed by a Cerenkov detector and leaves only a narrow range unexplored beyond the energy range studied by EGRET.",

keywords = "Gamma rays: observations, ISM: individual (Crab Nebula), Pulsars: individual (Crab Pulsar), Supernova remnants",

author = "\{De Naurois\}, M. and J. Holder and R. Bazer-Bachi and H. Bergeret and P. Bruel and A. Cordier and G. Debiais and Dezalay, \{J. P.\} and D. Dumora and E. Durand and P. Eschstruth and P. Espigat and B. Fahre and P. Fleury and N. H{\'e}rault and M. Hrabovsky and S. Incerti and \{Le Gallou\}, R. and F. M{\"u}nz and A. Musqu{\`e}re and Olive, \{J. F.\} and E. Par{\'e} and J. Qu{\'e}bert and Rannot, \{R. C.\} and T. Reposeur and L. Rob and P. Roy and T. Sako and P. Schovanek and Smith, \{D. A.\} and P. Snabre and A. Volte",

year = "2002",

month = feb,

day = "10",

doi = "10.1086/337991",

language = "English",

volume = "566",

pages = "343--357",

journal = "Astrophysical Journal",

issn = "0004-637X",

number = "1 I",

}

De Naurois, M, Holder, J, Bazer-Bachi, R, Bergeret, H, Bruel, P, Cordier, A, Debiais, G, Dezalay, JP, Dumora, D, Durand, E, Eschstruth, P, Espigat, P, Fahre, B, Fleury, P, Hérault, N, Hrabovsky, M, Incerti, S, Le Gallou, R, Münz, F, Musquère, A, Olive, JF, Paré, E, Québert, J, Rannot, RC, Reposeur, T, Rob, L, Roy, P, Sako, T, Schovanek, P, Smith, DA, Snabre, P & Volte, A 2002, 'Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope', Astrophysical Journal, vol. 566, no. 1 I, pp. 343-357. https://doi.org/10.1086/337991

TY - JOUR

T1 - Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope

AU - De Naurois, M.

AU - Holder, J.

AU - Bazer-Bachi, R.

AU - Bergeret, H.

AU - Bruel, P.

AU - Cordier, A.

AU - Debiais, G.

AU - Dezalay, J. P.

AU - Dumora, D.

AU - Durand, E.

AU - Eschstruth, P.

AU - Espigat, P.

AU - Fahre, B.

AU - Fleury, P.

AU - Hérault, N.

AU - Hrabovsky, M.

AU - Incerti, S.

AU - Le Gallou, R.

AU - Münz, F.

AU - Musquère, A.

AU - Olive, J. F.

AU - Paré, E.

AU - Québert, J.

AU - Rannot, R. C.

AU - Reposeur, T.

AU - Rob, L.

AU - Roy, P.

AU - Sako, T.

AU - Schovanek, P.

AU - Smith, D. A.

AU - Snabre, P.

AU - Volte, A.

PY - 2002/2/10

Y1 - 2002/2/10

N2 - We have converted the former solar electrical plant THEMIS (French Pyrenees) into an atmospheric Cerenkov detector called CELESTE, which records gamma rays above 30 GeV (7 × 1024 Hz). Here we present the first sub-100 GeV detection by a ground-based telescope of a gamma-ray source, the Crab Nebula, in the energy region between satellite measurements and imaging atmospheric Cerenkov telescopes. At our analysis threshold energy of 60 ± 20 GeV we measure a gamma-ray rate of 6.1 ± 0.8 minute -1. Allowing for 30% systematic uncertainties and a 30% error on the energy scale yields an integral gamma-ray flux of I(E > 60GeV) = 6.2 -2.3+5.3 × 10-6 photons m-2 s-1. The analysis methods used to obtain the gamma-ray signal from the raw data are detailed. In addition, we determine the upper limit for pulsed emission to be less than 12% of the Crab flux at the 99% confidence level, in the same energy range. Our result indicates that if the power law observed by EGRET is attenuated by a cutoff of form e-E/E0, then E0 < 26 GeV. This is the lowest energy probed by a Cerenkov detector and leaves only a narrow range unexplored beyond the energy range studied by EGRET.

AB - We have converted the former solar electrical plant THEMIS (French Pyrenees) into an atmospheric Cerenkov detector called CELESTE, which records gamma rays above 30 GeV (7 × 1024 Hz). Here we present the first sub-100 GeV detection by a ground-based telescope of a gamma-ray source, the Crab Nebula, in the energy region between satellite measurements and imaging atmospheric Cerenkov telescopes. At our analysis threshold energy of 60 ± 20 GeV we measure a gamma-ray rate of 6.1 ± 0.8 minute -1. Allowing for 30% systematic uncertainties and a 30% error on the energy scale yields an integral gamma-ray flux of I(E > 60GeV) = 6.2 -2.3+5.3 × 10-6 photons m-2 s-1. The analysis methods used to obtain the gamma-ray signal from the raw data are detailed. In addition, we determine the upper limit for pulsed emission to be less than 12% of the Crab flux at the 99% confidence level, in the same energy range. Our result indicates that if the power law observed by EGRET is attenuated by a cutoff of form e-E/E0, then E0 < 26 GeV. This is the lowest energy probed by a Cerenkov detector and leaves only a narrow range unexplored beyond the energy range studied by EGRET.

KW - Gamma rays: observations

KW - ISM: individual (Crab Nebula)

KW - Pulsars: individual (Crab Pulsar)

KW - Supernova remnants

UR - https://www.scopus.com/pages/publications/18244421345

U2 - 10.1086/337991

DO - 10.1086/337991

M3 - Article

AN - SCOPUS:18244421345

SN - 0004-637X

VL - 566

SP - 343

EP - 357

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 1 I

ER -

Measurement of the Crab flux above 60 GeV with the Celeste Cerenkov telescope

Abstract

Keywords

Access to Document

Other files and links

Fingerprint

Cite this