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arXiv · 0906.5511

Oscillation Phenomena in the disk around the massive black hole Sagittarius A*

M. Miyoshi·Zhi-Qiang Shen·T. Oyama·R. Takahashi·Y. Kato
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Abstract

We report the detection of radio QPOs with structure changes using the Very Long Baseline Array (VLBA) at 43 GHz. We found conspicuous patterned changes of the structure with P = 16.8 +- 1.4, 22.2 +- 1.4, 31.2 +- 1.5, 56.4 +- 6 min, very roughly in a 3:4:6:10 ratio. The first two periods show a rotating one-arm structure, while the P = 31.4 min shows a rotating 3-arm structure, as if viewed edge-on. At the central 50 microasec the P = 56.4 min period shows a double amplitude variation of those in its surroundings. Spatial distributions of the oscillation periods suggest that the disk of SgrA* is roughly edge-on, rotating around an axis with PA = -10 degree. Presumably, the observed VLBI images of SgrA* at 43 GHz retain several features of the black hole accretion disk of SgrA* in spite of being obscured and broadened by scattering of surrounding plasma.

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M. Miyoshi, Zhi-Qiang Shen, T. Oyama, R. Takahashi, Y. Kato. 2009-06-30. Oscillation Phenomena in the disk around the massive black hole Sagittarius A*. https://arxiv.org/abs/0906.5511

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