Submillimeter Quasi-Periodic Oscillations in Magnetically Choked Accretion Flows Models of Sgr A*

High-frequency quasi-periodic oscillations (QPOs) appear in general-relativistic magnetohydrodynamic simulations of magnetically choked accretion flows around rapidly rotating black holes (BHs). We perform polarized radiative transfer calculations with ASTRORAY code to explore the manifestations of these QPOs for SgrA*. We construct a simulation-based model of a radiatively inefficient accretion flow and find model parameters by fitting the mean polarized source spectrum. The simulated QPOs have a total sub-mm flux amplitude up to 5% and a linearly polarized flux amplitude up to 2%. The oscillations reach high levels of significance 10-30σand high quality factors Q~5. The oscillation period T~100M~35min corresponds to the rotation period of the BH magnetosphere that produces a trailing spiral in resolved disk images. The total flux signal is significant over noise for all tested frequencies 87GHz, 230GHz, and 857GHz and inclination angles 10deg, 37deg, and 80deg. The non-detection in the 230GHz Sub-Millimeter Array light curve is consistent with a low signal level and a low sampling rate. The presence of sub-mm QPOs in SgrA* will be better tested with the Atacama Large Millimeter Array.

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