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arXiv · astro-ph/0408190

Hard X-ray view of the past activity of Sgr A* in a natural Compton mirror

M. G. Revnivtsev·E. M. Churazov·S. Yu. Sazonov·R. A. Sunyaev·A. A. Lutovinov·M. R. Gilfanov·A. A. Vikhlinin·P. E. Shtykovsky·M. N. Pavlinsky
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Abstract

We report the association of the recently discovered hard X-ray source IGR J17475-2822 with the giant molecular cloud Sgr B2 in the Galactic Center region. The broad band (3-200 keV) spectrum of the source constructed from data of different observatories strongly supports the idea that the X-ray emission of Sgr B2 is Compton scattered and reprocessed radiation emitted in the past by the Sgr A* source. We conclude that 300-400 years ago Sgr A* was a low luminosity (L ~ 1.5e39 erg/s at 2-200 keV) AGN with a characteristic hard X-ray spectrum (photon index Gamma ~ 1.8). We estimate the mass and iron abundance of the Sgr B2 scattering gas at 2e6 Msun (r/10pc)^2 and 1.9 solar, respectively (where r is the radius of the cloud).

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M. G. Revnivtsev, E. M. Churazov, S. Yu. Sazonov, R. A. Sunyaev, A. A. Lutovinov, M. R. Gilfanov, A. A. Vikhlinin, P. E. Shtykovsky, M. N. Pavlinsky. 2004-08-10. Hard X-ray view of the past activity of Sgr A* in a natural Compton mirror. https://doi.org/10.1051/0004-6361%3A200400064

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