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Type: Journal article
Title: Simultaneous HESS and Chandra observations of Sagitarius A(star) during an X-ray flare
Author: Aharonian, F.
Akhperjanian, A.
Barres de Almaida, U.
Bazer-Bachi, A.
Becherini, Y.
Behera, B.
Benbow, W.
Bernlohr, K.
Boisson, C.
Bochow, A.
Borrel, V.
Braun, I.
Brion, E.
Brucker, J.
Brun, P.
Buhler, R.
Bulik, T.
Busching, I.
Boutelier, T.
Carrigan, S.
et al.
Citation: Astronomy and Astrophysics: a European journal, 2008; 492(1):L25-L28
Publisher: EDP Sciences
Issue Date: 2008
ISSN: 0004-6361
Statement of
F. Aharonian, A. G. Akhperjanian, U. Barres de Almeida, A. R. Bazer-Bachi, Y. Becherini ... Gavin P. Rowell ... et al.
Abstract: The rapidly varying (∼10 min timescale) non-thermal X-ray emission observed from Sgr A implies that particle acceleration is occuring close to the event horizon of the supermassive black hole. The TeV γ-ray source HESS J1745−290 is coincident with Sgr A and may be closely related to its X-ray emission. Simultaneous X-ray and TeV observations are required to elucidate the relationship between these objects. We report on joint HESS/Chandra observations performed in July 2005, during which an X-ray flare was detected. Despite a factor of ≈9 increase in the X-ray flux of Sgr A , no evidence is found for an increase in the TeV γ-ray flux from this region. We find that an increase in the γ-ray flux of a factor of 2 or greater can be excluded at a confidence level of 99%. This finding disfavours scenarios in which the keV and TeV emission are associated with the same population of accelerated particles and in which the bulk of the γ-ray emission is produced within ∼1014 cm (∼100 RS) of the supermassive black hole.
Keywords: gamma rays: observations
X-rays: individuals: Sgr A*
Description: Copyright © ESO 2008
Rights: Copyright © ESO 2008
DOI: 10.1051/0004-6361:200810912
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Appears in Collections:Aurora harvest
Chemistry and Physics publications

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