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arXiv · 1311.6818

The 3 Ms Chandra Campaign on Sgr A*: A Census of X-ray Flaring Activity from the Galactic Center

J. Neilsen·M. A. Nowak·C. Gammie·J. Dexter·S. Markoff·D. Haggard·S. Nayakshin·Q. D. Wang·N. Grosso·D. Porquet·J. A. Tomsick·N. Degenaar·P. C. Fragile·J. C. Houck·R. Wijnands·J. M. Miller·F. K. Baganoff
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Abstract

Over the last decade, X-ray observations of Sgr A* have revealed a black hole in a deep sleep, punctuated roughly once per day by brief flares. The extreme X-ray faintness of this supermassive black hole has been a long-standing puzzle in black hole accretion. To study the accretion processes in the Galactic Center, Chandra (in concert with numerous ground- and space-based observatories) undertook a 3 Ms campaign on Sgr A* in 2012. With its excellent observing cadence, sensitivity, and spectral resolution, this Chandra X-ray Visionary Project (XVP) provides an unprecedented opportunity to study the behavior of the closest supermassive black hole. We present a progress report from our ongoing study of X-ray flares, including the brightest flare ever seen from Sgr A*. Focusing on the statistics of the flares and the quiescent emission, we discuss the physical implications of X-ray variability in the Galactic Center.

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J. Neilsen, M. A. Nowak, C. Gammie, J. Dexter, S. Markoff, D. Haggard, S. Nayakshin, Q. D. Wang, N. Grosso, D. Porquet, J. A. Tomsick, N. Degenaar, P. C. Fragile, J. C. Houck, R. Wijnands, J. M. Miller, F. K. Baganoff. 2013-11-26. The 3 Ms Chandra Campaign on Sgr A*: A Census of X-ray Flaring Activity from the Galactic Center. https://doi.org/10.1017/s1743921314000945

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