The high-energy γ-ray emission of AP Librae

H.E.S.S. Collaboration

doi:10.1051/0004-6361/201321436

The high-energy γ-ray emission of AP Librae

H.E.S.S. Collaboration

Universität Hamburg
Max-Planck-Institut für Kernphysik
Dublin Institute for Advanced Studies
National Academy of Sciences of Armenia
Yerevan Physics Institute
Humboldt-Universität zu Berlin
Friedrich-Alexander University (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen
University of Namibia
Durham University
c/o DESY
University of Potsdam
Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences
Linnaeus University, Växjö
Ruhr-University Bochum
University of Innsbruck
University of California at Santa Cruz
North-West University
LUTH - Laboratoire de l'Univers et de ses Theories
Universités Paris VI and VII
University of Tübingen
Universite Paris-Saclay
University of Warsaw
University of the Witwatersrand, Johannesburg
Landessternwarte Heidelberg
Stockholm University
Wallenberg Academy
Univ. Bordeaux
European Community
The University of Adelaide
Astroparticule and Cosmol APC
Université Grenoble Alpes
University of Leicester
Institute for Nuclear Physics
Laboratoire Univers et Particules de Montpellier
Université Savoie Mont Blanc
Jagiellonian University
Nicolaus Copernicus University
University of the Free State
Charles University
Naval Research Laboratory
Center for Astrophysics | Harvard & Smithsonian

Résultats de recherche: Contribution à un journal › Article › Revue par des pairs

17 Citations (Scopus)

Résumé

The γ-ray spectrum of the low-frequency-peaked BL Lac (LBL) object AP Librae is studied, following the discovery of very-high-energy (VHE; E > 100 GeV) γ-ray emission up to the TeV range by the H.E.S.S. experiment. This makes AP Librae one of the few VHE emitters of the LBL type. The measured spectrum yields a flux of (8.8 ± 1.5_stat ± 1.8_sys) × 10^-12 cm^-2 s^-1 above 130 GeV and a spectral index of Γ = 2.65 ± 0.19_stat ± 0.20_sys. This study also makes use of Fermi-LAT observations in the high energy (HE, E> 100 MeV) range, providing the longest continuous light curve (5 years) ever published on this source. The source underwent a flaring event between MJD 56 306-56 376 in the HE range, with a flux increase of a factor of 3.5 in the 14 day bin light curve and no significant variation in spectral shape with respect to the low-flux state. While the H.E.S.S. and (low state) Fermi-LAT fluxes are in good agreement where they overlap, a spectral curvature between the steep VHE spectrum and the Fermi-LAT spectrum is observed. The maximum of the γ-ray emission in the spectral energy distribution is located below the GeV energy range.

langue originale	Anglais
Numéro d'article	A31
journal	Astronomy and Astrophysics
Volume	573
Les DOIs	https://doi.org/10.1051/0004-6361/201321436
état	Publié - 1 janv. 2015

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10.1051/0004-6361/201321436

Contient cette citation

@article{3629a44a5c79442db8ffcb52830557ba,

title = "The high-energy γ-ray emission of AP Librae",

abstract = "The γ-ray spectrum of the low-frequency-peaked BL Lac (LBL) object AP Librae is studied, following the discovery of very-high-energy (VHE; E > 100 GeV) γ-ray emission up to the TeV range by the H.E.S.S. experiment. This makes AP Librae one of the few VHE emitters of the LBL type. The measured spectrum yields a flux of (8.8 ± 1.5stat ± 1.8sys) × 10-12 cm-2 s-1 above 130 GeV and a spectral index of Γ = 2.65 ± 0.19stat ± 0.20sys. This study also makes use of Fermi-LAT observations in the high energy (HE, E> 100 MeV) range, providing the longest continuous light curve (5 years) ever published on this source. The source underwent a flaring event between MJD 56 306-56 376 in the HE range, with a flux increase of a factor of 3.5 in the 14 day bin light curve and no significant variation in spectral shape with respect to the low-flux state. While the H.E.S.S. and (low state) Fermi-LAT fluxes are in good agreement where they overlap, a spectral curvature between the steep VHE spectrum and the Fermi-LAT spectrum is observed. The maximum of the γ-ray emission in the spectral energy distribution is located below the GeV energy range.",

keywords = "BL Lacertae objects: individual: AP Librae, Galaxies: active, Gamma rays: galaxies",

author = "\{H.E.S.S. Collaboration\} and A. Abramowski and F. Aharonian and \{Ait Benkhali\}, F. and Akhperjanian, \{A. G.\} and E. Ang{\"u}ner and G. Anton and M. Backes and S. Balenderan and A. Balzer and A. Barnacka and Y. Becherini and \{Becker Tjus\}, J. and K. Bernl{\"o}hr and E. Birsin and E. Bissaldi and J. Biteau and M. B{\"o}ttcher and C. Boisson and J. Bolmont and P. Bordas and J. Brucker and F. Brun and P. Brun and T. Bulik and S. Carrigan and S. Casanova and Chadwick, \{P. M.\} and R. Chalme-Calvet and Chaves, \{R. C.G.\} and A. Cheesebrough and M. Chr{\'e}tien and S. Colafrancesco and G. Cologna and J. Conrad and C. Couturier and Y. Cui and M. Dalton and Daniel, \{M. K.\} and Davids, \{I. D.\} and B. Degrange and C. Deil and P. Dewilt and Dickinson, \{H. J.\} and A. Djannati-Ata{\"i} and W. Domainko and Drury, \{L. O.c.\} and G. Dubus and K. Dutson and S. Fegan and D. Horan",

note = "Publisher Copyright: {\textcopyright} ESO, 2014.",

year = "2015",

month = jan,

day = "1",

doi = "10.1051/0004-6361/201321436",

language = "English",

volume = "573",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

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TY - JOUR

T1 - The high-energy γ-ray emission of AP Librae

AU - H.E.S.S. Collaboration

AU - Abramowski, A.

AU - Aharonian, F.

AU - Ait Benkhali, F.

AU - Akhperjanian, A. G.

AU - Angüner, E.

AU - Anton, G.

AU - Backes, M.

AU - Balenderan, S.

AU - Balzer, A.

AU - Barnacka, A.

AU - Becherini, Y.

AU - Becker Tjus, J.

AU - Bernlöhr, K.

AU - Birsin, E.

AU - Bissaldi, E.

AU - Biteau, J.

AU - Böttcher, M.

AU - Boisson, C.

AU - Bolmont, J.

AU - Bordas, P.

AU - Brucker, J.

AU - Brun, F.

AU - Brun, P.

AU - Bulik, T.

AU - Carrigan, S.

AU - Casanova, S.

AU - Chadwick, P. M.

AU - Chalme-Calvet, R.

AU - Chaves, R. C.G.

AU - Cheesebrough, A.

AU - Chrétien, M.

AU - Colafrancesco, S.

AU - Cologna, G.

AU - Conrad, J.

AU - Couturier, C.

AU - Cui, Y.

AU - Dalton, M.

AU - Daniel, M. K.

AU - Davids, I. D.

AU - Degrange, B.

AU - Deil, C.

AU - Dewilt, P.

AU - Dickinson, H. J.

AU - Djannati-Ataï, A.

AU - Domainko, W.

AU - Drury, L. O.c.

AU - Dubus, G.

AU - Dutson, K.

AU - Fegan, S.

AU - Horan, D.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - The γ-ray spectrum of the low-frequency-peaked BL Lac (LBL) object AP Librae is studied, following the discovery of very-high-energy (VHE; E > 100 GeV) γ-ray emission up to the TeV range by the H.E.S.S. experiment. This makes AP Librae one of the few VHE emitters of the LBL type. The measured spectrum yields a flux of (8.8 ± 1.5stat ± 1.8sys) × 10-12 cm-2 s-1 above 130 GeV and a spectral index of Γ = 2.65 ± 0.19stat ± 0.20sys. This study also makes use of Fermi-LAT observations in the high energy (HE, E> 100 MeV) range, providing the longest continuous light curve (5 years) ever published on this source. The source underwent a flaring event between MJD 56 306-56 376 in the HE range, with a flux increase of a factor of 3.5 in the 14 day bin light curve and no significant variation in spectral shape with respect to the low-flux state. While the H.E.S.S. and (low state) Fermi-LAT fluxes are in good agreement where they overlap, a spectral curvature between the steep VHE spectrum and the Fermi-LAT spectrum is observed. The maximum of the γ-ray emission in the spectral energy distribution is located below the GeV energy range.

AB - The γ-ray spectrum of the low-frequency-peaked BL Lac (LBL) object AP Librae is studied, following the discovery of very-high-energy (VHE; E > 100 GeV) γ-ray emission up to the TeV range by the H.E.S.S. experiment. This makes AP Librae one of the few VHE emitters of the LBL type. The measured spectrum yields a flux of (8.8 ± 1.5stat ± 1.8sys) × 10-12 cm-2 s-1 above 130 GeV and a spectral index of Γ = 2.65 ± 0.19stat ± 0.20sys. This study also makes use of Fermi-LAT observations in the high energy (HE, E> 100 MeV) range, providing the longest continuous light curve (5 years) ever published on this source. The source underwent a flaring event between MJD 56 306-56 376 in the HE range, with a flux increase of a factor of 3.5 in the 14 day bin light curve and no significant variation in spectral shape with respect to the low-flux state. While the H.E.S.S. and (low state) Fermi-LAT fluxes are in good agreement where they overlap, a spectral curvature between the steep VHE spectrum and the Fermi-LAT spectrum is observed. The maximum of the γ-ray emission in the spectral energy distribution is located below the GeV energy range.

KW - BL Lacertae objects: individual: AP Librae

KW - Galaxies: active

KW - Gamma rays: galaxies

U2 - 10.1051/0004-6361/201321436

DO - 10.1051/0004-6361/201321436

M3 - Article

AN - SCOPUS:84936998181

SN - 0004-6361

VL - 573

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A31

ER -

The high-energy γ-ray emission of AP Librae

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