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Conference papers

Variable Hard X-Ray Emission from the Sgr B2 Molecular Cloud

R. Terrier 1 G. Ponti 2 G. Belanger 3 A. Decourchelle 4 V. Tatischeff 5 A. Goldwurm 1 G. Trap 6, 2, 4
1 APC - AHE - APC - Astrophysique des Hautes Energies
APC (UMR_7164) - AstroParticule et Cosmologie, Dipartimento di Astronomia, Universita degli Studi di Bologna
CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CSNSM - Centre de Sciences Nucléaires et de Sciences de la Matière
Abstract : The 4 million solar masses black hole at the Galactic centre (GC) is remarkably quiet today. The molecular cloud Sgr B2, among others, emits strong Fe K alpha photons as well as hard X-rays up to 100 keV. This has been interpreted as the result of the illumination of the cloud by a past high luminosity period of Sgr A*. This interpretation is still controversial since irradiation by subrelativistic cosmic rays might also account for the observed spectra. We present here the results of 7 years of INTEGRAL monitoring of Sgr B2 and show that its hard X-ray (20-60 keV) flux has decreased by nearly 40% during that period. This cannot be accounted for by cosmic ray interpretations and support the idea that Sgr A* was more active in the past and has been quiescent since about 100 years.
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Submitted on : Friday, December 9, 2011 - 4:11:18 PM
Last modification on : Monday, December 13, 2021 - 9:15:21 AM


  • HAL Id : in2p3-00650274, version 1


R. Terrier, G. Ponti, G. Belanger, A. Decourchelle, V. Tatischeff, et al.. Variable Hard X-Ray Emission from the Sgr B2 Molecular Cloud. Conference on the Galactic Center: A Window to the Nuclear Environment of Disk Galaxies, 2009, Shanghai, China. pp.442-445. ⟨in2p3-00650274⟩



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