The Phys.org article Cosmic filament probes our galaxy's giant black hole links to A Nonthermal Radio Filament Connected to the Galactic Black Hole? which discusses (among other things) the importance of achieving high dynamic range to study these filaments in the proximity of the strong emission associated with Sgr A*. It mentions the fluctuation of radio intensity from Sgr A* on time scales as short as five minutes (as well as to instrumental time-varying effects that also require attention and calibration).

The paper refers to Zhao et al. 2016, which in turn links to Zhao et al. 1999. But so far I can't track down either the nature of the short term variations seen in the radio brightness of Sgr A* nor the mechanism.

What is the nature of this variation (amplitude, power spectrum, any periodicity?) and what are the proposed mechanisms?

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    $\begingroup$ One would have to dig into the literature to find out, but my a priori guess would be that there aren't good explanations. There may be no good answer to this question. $\endgroup$ – zephyr Dec 23 '17 at 19:27
  • $\begingroup$ @zephyr thanks. I suppose it could be at least categorized as either related to the generation mechanism, or to some kind of radio scintillation occurring along the line of sight through the galaxy. I'll try to do some reading also. $\endgroup$ – uhoh Dec 24 '17 at 3:43
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    $\begingroup$ Recent bright flash, May 13 2019, could be basis for a more targeted question, probably still only with speculative answer. sciencealert.com/… and arxiv arxiv.org/abs/1908.01777 . $\endgroup$ – bitchaser Sep 22 at 1:48
  • $\begingroup$ @bitchaser that's a great idea, I'll update this today, thanks! (only slightly related: How did they make a video of the center of the galaxy, and what is it exactly that's flashing there?) $\endgroup$ – uhoh Sep 22 at 1:58

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