Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes

J. Aleksić; S. Ansoldi; L. A. Antonelli; P. Antoranz; A. Babic; P. Bangale; J. A. Barrio; J. Becerra González; W. Bednarek; E. Bernardini; B. Biasuzzi; A. Biland; O. Blanch; S. Bonnefoy; G. Bonnoli; F. Borracci; T. Bretz; E. Carmona; A. Carosi; P. Colin; E. Colombo; J. L. Contreras; J. Cortina; S. Covino; P. Da Vela; F. Dazzi; A. De Angelis; G. De Caneva; B. De Lotto; E. de Oña Wilhelmi; C. Delgado Mendez; M. Doert; D. Dominis Prester; D. Dorner; M. Doro; S. Einecke; D. Eisenacher; D. Elsaesser; M. V. Fonseca; L. Font; K. Frantzen; C. Fruck; D. Galindo; R. J. García López; M. Garczarczyk; D. Garrido Terrats; M. Gaug; N. Godinović; A. González Muñoz; S. R. Gozzini; D. Hadasch; Y. Hanabata; M. Hayashida; J. Herrera; D. Hildebrand; J. Hose; D. Hrupec; W. Idec; V. Kadenius; H. Kellermann; K. Kodani; Y. Konno; J. Krause; H. Kubo; J. Kushida; A. La Barbera; D. Lelas; N. Lewandowska; E. Lindfors; S. Lombardi; M. López; R. López-Coto; A. López-Oramas; E. Lorenz; I. Lozano; M. Makariev; K. Mallot; G. Maneva; N. Mankuzhiyil; K. Mannheim; L. Maraschi; B. Marcote; M. Mariotti; M. Martínez; D. Mazin; U. Menzel; J. M. Miranda; R. Mirzoyan; A. Moralejo; P. Munar-Adrover; D. Nakajima; A. Niedzwiecki; K. Nilsson; K. Nishijima; K. Noda; N. Nowak; R. Orito; A. Overkemping; S. Paiano; M. Palatiello

doi:10.1016/j.jheap.2015.01.002

Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes

J. Aleksić, S. Ansoldi, L. A. Antonelli, P. Antoranz, A. Babic, P. Bangale, J. A. Barrio, J. Becerra González, W. Bednarek, E. Bernardini, B. Biasuzzi, A. Biland, O. Blanch, S. Bonnefoy, G. Bonnoli, F. Borracci, T. Bretz, E. Carmona, A. Carosi, P. ColinE. Colombo, J. L. Contreras, J. Cortina, S. Covino, P. Da Vela, F. Dazzi, A. De Angelis, G. De Caneva, B. De Lotto, E. de Oña Wilhelmi, C. Delgado Mendez, M. Doert, D. Dominis Prester, D. Dorner, M. Doro, S. Einecke, D. Eisenacher, D. Elsaesser, M. V. Fonseca, L. Font, K. Frantzen, C. Fruck, D. Galindo, R. J. García López, M. Garczarczyk, D. Garrido Terrats, M. Gaug, N. Godinović, A. González Muñoz, S. R. Gozzini, D. Hadasch, Y. Hanabata, M. Hayashida, J. Herrera, D. Hildebrand, J. Hose, D. Hrupec, W. Idec, V. Kadenius, H. Kellermann, K. Kodani, Y. Konno, J. Krause, H. Kubo, J. Kushida, A. La Barbera, D. Lelas, N. Lewandowska, E. Lindfors, S. Lombardi, M. López, R. López-Coto, A. López-Oramas, E. Lorenz, I. Lozano, M. Makariev, K. Mallot, G. Maneva, N. Mankuzhiyil, K. Mannheim, L. Maraschi, B. Marcote, M. Mariotti, M. Martínez, D. Mazin, U. Menzel, J. M. Miranda, R. Mirzoyan, A. Moralejo, P. Munar-Adrover, D. Nakajima, A. Niedzwiecki, K. Nilsson, K. Nishijima, K. Noda, N. Nowak, R. Orito, A. Overkemping, S. Paiano, M. Palatiello

Institut de Física d'Altes Energies (IFAE)

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

74 Citations (Scopus)

Abstract

© 2015 Elsevier B.V.. The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (χred2=35/26). Using systematic uncertainties of the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53±3stat+31syst-13syst) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state-of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 μG magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.

Original language	English
Pages (from-to)	30-38
Journal	Journal of High Energy Astrophysics
Volume	5-6
DOIs	https://doi.org/10.1016/j.jheap.2015.01.002
Publication status	Published - 1 Jan 2015

Keywords

Crab Nebula
Imaging atmospheric Cherenkov telescopes
MAGIC telescopes
Pulsar wind nebulae
Very high energy gamma rays

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10.1016/j.jheap.2015.01.002

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Aleksić, J., Ansoldi, S., Antonelli, L. A., Antoranz, P., Babic, A., Bangale, P., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Borracci, F., Bretz, T., Carmona, E., Carosi, A., ... Palatiello, M. (2015). Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes. Journal of High Energy Astrophysics, 5-6, 30-38. https://doi.org/10.1016/j.jheap.2015.01.002

@article{722c37892e2049ffbb858c7ba085d64f,

title = "Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes",

abstract = "{\textcopyright} 2015 Elsevier B.V.. The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (χred2=35/26). Using systematic uncertainties of the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53±3stat+31syst-13syst) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state-of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 μG magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.",

keywords = "Crab Nebula, Imaging atmospheric Cherenkov telescopes, MAGIC telescopes, Pulsar wind nebulae, Very high energy gamma rays",

author = "J. Aleksi{\'c} and S. Ansoldi and Antonelli, {L. A.} and P. Antoranz and A. Babic and P. Bangale and Barrio, {J. A.} and {Becerra Gonz{\'a}lez}, J. and W. Bednarek and E. Bernardini and B. Biasuzzi and A. Biland and O. Blanch and S. Bonnefoy and G. Bonnoli and F. Borracci and T. Bretz and E. Carmona and A. Carosi and P. Colin and E. Colombo and Contreras, {J. L.} and J. Cortina and S. Covino and {Da Vela}, P. and F. Dazzi and {De Angelis}, A. and {De Caneva}, G. and {De Lotto}, B. and {de O{\~n}a Wilhelmi}, E. and {Delgado Mendez}, C. and M. Doert and {Dominis Prester}, D. and D. Dorner and M. Doro and S. Einecke and D. Eisenacher and D. Elsaesser and Fonseca, {M. V.} and L. Font and K. Frantzen and C. Fruck and D. Galindo and {Garc{\'i}a L{\'o}pez}, {R. J.} and M. Garczarczyk and {Garrido Terrats}, D. and M. Gaug and N. Godinovi{\'c} and {Gonz{\'a}lez Mu{\~n}oz}, A. and Gozzini, {S. R.} and D. Hadasch and Y. Hanabata and M. Hayashida and J. Herrera and D. Hildebrand and J. Hose and D. Hrupec and W. Idec and V. Kadenius and H. Kellermann and K. Kodani and Y. Konno and J. Krause and H. Kubo and J. Kushida and {La Barbera}, A. and D. Lelas and N. Lewandowska and E. Lindfors and S. Lombardi and M. L{\'o}pez and R. L{\'o}pez-Coto and A. L{\'o}pez-Oramas and E. Lorenz and I. Lozano and M. Makariev and K. Mallot and G. Maneva and N. Mankuzhiyil and K. Mannheim and L. Maraschi and B. Marcote and M. Mariotti and M. Mart{\'i}nez and D. Mazin and U. Menzel and Miranda, {J. M.} and R. Mirzoyan and A. Moralejo and P. Munar-Adrover and D. Nakajima and A. Niedzwiecki and K. Nilsson and K. Nishijima and K. Noda and N. Nowak and R. Orito and A. Overkemping and S. Paiano and M. Palatiello",

year = "2015",

month = jan,

day = "1",

doi = "10.1016/j.jheap.2015.01.002",

language = "English",

volume = "5-6",

pages = "30--38",

journal = "Journal of High Energy Astrophysics",

issn = "2214-4048",

publisher = "Elsevier BV",

}

Aleksić, J, Ansoldi, S, Antonelli, LA, Antoranz, P, Babic, A, Bangale, P, Barrio, JA, Becerra González, J, Bednarek, W, Bernardini, E, Biasuzzi, B, Biland, A, Blanch, O, Bonnefoy, S, Bonnoli, G, Borracci, F, Bretz, T, Carmona, E, Carosi, A, Colin, P, Colombo, E, Contreras, JL, Cortina, J, Covino, S, Da Vela, P, Dazzi, F, De Angelis, A, De Caneva, G, De Lotto, B, de Oña Wilhelmi, E, Delgado Mendez, C, Doert, M, Dominis Prester, D, Dorner, D, Doro, M, Einecke, S, Eisenacher, D, Elsaesser, D, Fonseca, MV, Font, L, Frantzen, K, Fruck, C, Galindo, D, García López, RJ, Garczarczyk, M, Garrido Terrats, D, Gaug, M, Godinović, N, González Muñoz, A, Gozzini, SR, Hadasch, D, Hanabata, Y, Hayashida, M, Herrera, J, Hildebrand, D, Hose, J, Hrupec, D, Idec, W, Kadenius, V, Kellermann, H, Kodani, K, Konno, Y, Krause, J, Kubo, H, Kushida, J, La Barbera, A, Lelas, D, Lewandowska, N, Lindfors, E, Lombardi, S, López, M, López-Coto, R, López-Oramas, A, Lorenz, E, Lozano, I, Makariev, M, Mallot, K, Maneva, G, Mankuzhiyil, N, Mannheim, K, Maraschi, L, Marcote, B, Mariotti, M, Martínez, M, Mazin, D, Menzel, U, Miranda, JM, Mirzoyan, R, Moralejo, A, Munar-Adrover, P, Nakajima, D, Niedzwiecki, A, Nilsson, K, Nishijima, K, Noda, K, Nowak, N, Orito, R, Overkemping, A, Paiano, S & Palatiello, M 2015, 'Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes', Journal of High Energy Astrophysics, vol. 5-6, pp. 30-38. https://doi.org/10.1016/j.jheap.2015.01.002

TY - JOUR

T1 - Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes

AU - Aleksić, J.

AU - Ansoldi, S.

AU - Antonelli, L. A.

AU - Antoranz, P.

AU - Babic, A.

AU - Bangale, P.

AU - Barrio, J. A.

AU - Becerra González, J.

AU - Bednarek, W.

AU - Bernardini, E.

AU - Biasuzzi, B.

AU - Biland, A.

AU - Blanch, O.

AU - Bonnefoy, S.

AU - Bonnoli, G.

AU - Borracci, F.

AU - Bretz, T.

AU - Carmona, E.

AU - Carosi, A.

AU - Colin, P.

AU - Colombo, E.

AU - Contreras, J. L.

AU - Cortina, J.

AU - Covino, S.

AU - Da Vela, P.

AU - Dazzi, F.

AU - De Angelis, A.

AU - De Caneva, G.

AU - De Lotto, B.

AU - de Oña Wilhelmi, E.

AU - Delgado Mendez, C.

AU - Doert, M.

AU - Dominis Prester, D.

AU - Dorner, D.

AU - Doro, M.

AU - Einecke, S.

AU - Eisenacher, D.

AU - Elsaesser, D.

AU - Fonseca, M. V.

AU - Font, L.

AU - Frantzen, K.

AU - Fruck, C.

AU - Galindo, D.

AU - García López, R. J.

AU - Garczarczyk, M.

AU - Garrido Terrats, D.

AU - Gaug, M.

AU - Godinović, N.

AU - González Muñoz, A.

AU - Gozzini, S. R.

AU - Hadasch, D.

AU - Hanabata, Y.

AU - Hayashida, M.

AU - Herrera, J.

AU - Hildebrand, D.

AU - Hose, J.

AU - Hrupec, D.

AU - Idec, W.

AU - Kadenius, V.

AU - Kellermann, H.

AU - Kodani, K.

AU - Konno, Y.

AU - Krause, J.

AU - Kubo, H.

AU - Kushida, J.

AU - La Barbera, A.

AU - Lelas, D.

AU - Lewandowska, N.

AU - Lindfors, E.

AU - Lombardi, S.

AU - López, M.

AU - López-Coto, R.

AU - López-Oramas, A.

AU - Lorenz, E.

AU - Lozano, I.

AU - Makariev, M.

AU - Mallot, K.

AU - Maneva, G.

AU - Mankuzhiyil, N.

AU - Mannheim, K.

AU - Maraschi, L.

AU - Marcote, B.

AU - Mariotti, M.

AU - Martínez, M.

AU - Mazin, D.

AU - Menzel, U.

AU - Miranda, J. M.

AU - Mirzoyan, R.

AU - Moralejo, A.

AU - Munar-Adrover, P.

AU - Nakajima, D.

AU - Niedzwiecki, A.

AU - Nilsson, K.

AU - Nishijima, K.

AU - Noda, K.

AU - Nowak, N.

AU - Orito, R.

AU - Overkemping, A.

AU - Paiano, S.

AU - Palatiello, M.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - © 2015 Elsevier B.V.. The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (χred2=35/26). Using systematic uncertainties of the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53±3stat+31syst-13syst) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state-of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 μG magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.

AB - © 2015 Elsevier B.V.. The MAGIC stereoscopic system collected 69 hours of Crab Nebula data between October 2009 and April 2011. Analysis of this data sample using the latest improvements in the MAGIC stereoscopic software provided an unprecedented precision of spectral and night-by-night light curve determination at gamma rays. We derived a differential spectrum with a single instrument from 50 GeV up to almost 30 TeV with 5 bins per energy decade. At low energies, MAGIC results, combined with Fermi-LAT data, show a flat and broad Inverse Compton peak. The overall fit to the data between 1 GeV and 30 TeV is not well described by a log-parabola function. We find that a modified log-parabola function with an exponent of 2.5 instead of 2 provides a good description of the data (χred2=35/26). Using systematic uncertainties of the MAGIC and Fermi-LAT measurements we determine the position of the Inverse Compton peak to be at (53±3stat+31syst-13syst) GeV, which is the most precise estimation up to date and is dominated by the systematic effects. There is no hint of the integral flux variability on daily scales at energies above 300 GeV when systematic uncertainties are included in the flux measurement. We consider three state-of-the-art theoretical models to describe the overall spectral energy distribution of the Crab Nebula. The constant B-field model cannot satisfactorily reproduce the VHE spectral measurements presented in this work, having particular difficulty reproducing the broadness of the observed IC peak. Most probably this implies that the assumption of the homogeneity of the magnetic field inside the nebula is incorrect. On the other hand, the time-dependent 1D spectral model provides a good fit of the new VHE results when considering a 80 μG magnetic field. However, it fails to match the data when including the morphology of the nebula at lower wavelengths.

KW - Crab Nebula

KW - Imaging atmospheric Cherenkov telescopes

KW - MAGIC telescopes

KW - Pulsar wind nebulae

KW - Very high energy gamma rays

U2 - 10.1016/j.jheap.2015.01.002

DO - 10.1016/j.jheap.2015.01.002

M3 - Article

SN - 2214-4048

VL - 5-6

SP - 30

EP - 38

JO - Journal of High Energy Astrophysics

JF - Journal of High Energy Astrophysics

ER -

Measurement of the Crab Nebula spectrum over three decades in energy with the MAGIC telescopes

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Keywords

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