Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/21114
Title: First detection of a VHE gamma-ray spectral maximum from a cosmic source: HESS discovery of the Vela X nebula
Authors: Aharonian, F.
Benbow, W.
Berge, D.
Bernlöhr, K.
Bolz, O.
Braun, I.
Bühler, R.
Carrigan, S.
Costamante, L.
Egberts, K.
Funk, S.
Masterson, C.
Ouchrif, M.
Tluczykont, M.
Hermann, G.
Hinton, J. A.
Hofmann, W.
Khélifi, B.
Masterson, C.
Panter, M.
Rowell, G.
Sahakian, V.
van Eldik C
Völk, H. J.
Akhperjanian, A. G.
Bazer-Bachi, A. R.
Borrel, V.
Marcowith, A.
Beilicke, M.
Cornils, R.
Heinzelmann, G.
Raue, M.
Ripken, J.
Bernlöhr, K.
Konopelko, A.
Breitling, F.
Funk, S.
Komin, N.
Lohse, T.
Schlenker, S.
Schwanke, U.
Stegmann, C.
Boisson, C.
Martin, J. M.
Sol, H.
Brown, A. M.
Chadwick, P. M.
le Gallou R
Dickinson, H. J.
Hadjichristidis, C.
Latham, I. J.
McComb, T. J. L.
Nolan, S. J.
Noutsos, A.
Orford, K. J.
Osborne, J. L.
Rayner, S. M.
Spangler, D.
Ward, M.
Büsching, I.
Venter, C.
Holleran, M.
de Jager OC
Raubenheimer, B. C.
Chounet, L. -. M.
Degrange, B.
Dubus, G.
Fontaine, G.
Giebels, B.
Khélifi, B.
Lemoine-Goumard, M.
Superina, G.
Tluczykont, M.
Pita, S.
Djannati-Ataï, A.
Espigat, P.
Lemière, A.
Punch, M.
Terrier, R.
Théoret, C. G.
Drury, L. O.
Emmanoulopoulos, D.
Ferrero, E.
Hauser, M.
Hinton, J. A.
Pühlhofer, G.
Gallant, Y. A.
Wagner, S. J.
Epinat, B.
Feinstein, F.
Jacholkowska, A.
Vasileiadis, G.
Glicenstein, J. F.
Goret, P.
Rolland, L.
Henri, G.
Pelletier, G.
Saugé, L.
Horns, D.
Tavernet, J. -. P.
Martineau-Huynh, O.
de Naurois M
Ouchrif, M.
Vincent, P.
Nedbal, D.
Rob, L.
Reimer, A.
Reimer, O.
Schlickeiser, R.
Spanier, F.
Steenkamp, R.
Costamante, L.
Hauser, D.
First Published: Mar-2006
Publisher: EDP Sciences for European Southern Observatory (ESO)
Citation: Astronomy & Astrophysics, 2006, 448 (2)
Abstract: The Vela supernova remnant (SNR) is a complex region containing a number of sources of non-thermal radiation. The inner section of this SNR, within 2 degrees of the pulsar PSR B0833-45 , has been observed by the HESS $\gamma$-ray atmospheric Cherenkov detector in 2004 and 2005. A strong signal is seen from an extended region to the south of the pulsar, within an integration region of radius $0.8\ensuremath{^{\circ}} $ around the position ( $\rm\alpha = 08^{h} 35^{m} 00^{s}$, $\delta = -45\ensuremath{^{\circ}} 36\arcmin$ J2000.0). The excess coincides with a region of hard X-ray emission seen by the ROSAT and ASCA satellites. The observed energy spectrum of the source between 550 GeV and 65 TeV is well fit by a power law function with photon index $\Gamma = 1.45 \pm 0.09\ensuremath{_{{\rm stat}}}\ \pm 0.2\ensuremath{_{{\rm sys}}} $ and an exponential cutoff at an energy of $13.8 \pm 2.3\ensuremath{_{{\rm stat}}}\ \pm 4.1\ensuremath{_{{\rm sys}}} $ TeV. The integral flux above 1 TeV is $(1.28 \pm 0.17\ensuremath{_{{\rm stat}}}\ \pm 0.38\ensuremath{_{{\rm sys}}} ) \times 10^{-11}\ \ensuremath{{\rm cm}^{-2}\,{\rm s}^{-1}} $. This result is the first clear measurement of a peak in the spectral energy distribution from a VHE $\gamma$-ray source, likely related to inverse Compton emission. A fit of an Inverse Compton model to the HESS spectral energy distribution gives a total energy in non-thermal electrons of ~ $2 \times 10^{45}$ erg between 5 TeV and 100 TeV, assuming a distance of 290 parsec to the pulsar. The best fit electron power law index is 2.0, with a spectral break at 67 TeV.
DOI Link: 10.1051/0004-6361:200600014
ISSN: 0004-6361
eISSN: 1432-0746
Links: http://hdl.handle.net/2381/21114
http://www.aanda.org/articles/aa/abs/2006/11/aahl202/aahl202.html
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2006 ESO. Reproduced with permission from Astronomy & Astrophysics, © ESO.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

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