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arXiv · 1702.07903

A Possible Time-Delayed Brightening of the Sgr A* Accretion Flow after the Pericenter Passage of G2 Cloud

Tomohisa Kawashima·Yosuke Matsumoto·Ryoji Matsumoto
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Abstract

A possibility of time-delayed radio brightenings of Sgr A* triggered by the pericenter passage of the G2 cloud is studied by carrying out global three-dimensional magnetohydrodynamic simulations taking into account the radiative cooling of the tidal debris of the G2 cloud. Magnetic fields in the accretion flow are strongly perturbed and re-organized after the passage of G2. We have found that the magnetic energy in the accretion flow increases by a factor 3-4 in 5-10 years after the pericenter passage of G2 by a dynamo mechanism driven by the magneto-rotational instability. Since this B-field amplification enhances the synchrotron emission from the disk and the outflow, the radio and the infrared luminosity of Sgr A* is expected to increase around A.D. 2020. The time-delay of the radio brightening enables us to determine the rotation axis of the preexisting disk.

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Tomohisa Kawashima, Yosuke Matsumoto, Ryoji Matsumoto. 2017-04-10. A Possible Time-Delayed Brightening of the Sgr A* Accretion Flow after the Pericenter Passage of G2 Cloud. https://doi.org/10.1093/pasj%2Fpsx015

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