UNIVERSETODAY.COM | 2024 June 14
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Searching for Sgr A* X-ray Flares with NuSTAR Sanger-Johnson analyzed ten years’ worth of data looking for X-ray flares generated by Sgr A*’s eating habits. During the search, she found evidence for nine more such outbursts.
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The data Sanger-Johnson collected and analyzed is now a database of flares from Sgr A. “We hope that by building up this bank of data on Sgr A flares, we and other astronomers can analyze the properties of these X-ray flares and infer the physical conditions inside the extreme environment of the supermassive black hole,” Sanger-Johnson said.
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Tracking the Echoes of Flares While Sanger-Johnson was working with the NuSTAR data, undergraduate researcher Jack Uteg studied the activity around the black hole. He analyzed 20 years of data about a giant molecular cloud called “the Bridge”. The data came from observations made by NuSTAR and the European Space Agency’s XMM-Newton observatory. The Bridge lies close to Sgr A* and normally wouldn’t give off its own light.
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What Those Light-echoes from Sgr A* Reveal Thanks to Sanger-Brown and Uteg’s work, astronomers have another way around the difficulties of observing around black holes. “Both flares and fireworks light up the darkness and help us observe things we wouldn’t normally be able to,” she said. “That’s why astronomers need to know when and where these flares occur, so they can study the black hole’s environment using that light.”
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“This is the first time that we have constructed a 24-year-long variability for a molecular cloud surrounding our supermassive black hole that has reached its peak X-ray luminosity,” Zhang said. “It allows us to tell the past activity of Sgr A* from about 200 years ago. Our research team at MSU will continue this ‘astroarchaeology game’ to further unravel the mysteries of the Milky Way’s center.”
These results of the MSU team’s work were presented at the summer 2024 meeting of the American Astronomical Society.
https://www.universetoday.com/167397/ec ... lack-hole/
Astronomers do know about outbursts from Sgr A* from other observations. Here’s a view from NASA’s Imaging X-ray Polarimetry Explorer and Chandra X-ray Observatory. The combination of IXPE and Chandra data helped researchers determine that the X-ray light identified in the molecular clouds originated from Sagittarius A* during an outburst approximately 200 years ago.
Credits: IXPE: NASA/MSFC/F. Marin et al; Chandra: NASA/CXC/SAO; Image Processing: L.Frattare, J.Major & K.Arcand
