The research team believes that these flickers are coming out from the supermassive black hole and the reason behind it is the rotation of radio spots circling the supermassive black hole with an orbit radius smaller than the Mercury’s orbit.
Tomoharu Oka, a professor at Keio University in Japan said that this emission could be related to some exotic phenomena occurring in the very vicinity of the supermassive black hole.
Yuhei Iwata, the lead author of the research said, “This time, using the Atacama Large Millimeter/submillimeter Array (ALMA), we obtained high-quality data of radio-wave intensity variation of Sagittarius A* for 70 minutes per day for 10 days. Then we found two trends that were the quasi-periodic variations with a typical time scale of 30 minutes and hour-long slow variations.”
Iwata added, “It has been known that Sagittarius A* sometimes flares up in millimeter-wavelength.”
Flares of Sagittarius A* have also been observed in infrared light and X-ray.
Astronomers also believe that a supermassive black hole with a mass of 4 million suns is located at the center of Sagittarius A*.
Professor Oka said, “The faster the movement is, the more difficult it is to take a photo of the object. Instead, the variation of the emission itself provides compelling insight for the gas motion. We may witness the very moment of gas absorption by the black hole with a long-term monitoring campaign with ALMA.”
The researchers suppose that the variation might affect the effort to make an image of the supermassive black hole with the Event Horizon Telescope.