Bard Physics Professor Shuo Zhang Presents Research on Supermassive Black Hole at 2022 American Astronomical Society Press Conference
Though inactive nowadays, traces of a glorious past of Sgr A* can be found in the surrounding molecular gas clouds, which reflect incoming X-ray emission from Sgr A* up to a few hundred years ago. Therefore, by studying X-ray emission from molecular clouds at different distances from Sgr A*, we can reconstruct the activity history of Sgr A* in the past few centuries. Shuo Zhang and her post-bac researcher Nathalie Jones ’21 have focused their study on a particular Galactic center molecular cloud, the “Bridge”. Their analysis on archival data by the NuSTAR telescope during 2012-2020, and the XMM-Newton telescope data during 2000-2020 clearly demonstrates an epic 20-year-long X-ray brightening of the “Bridge” molecular cloud, making it currently the brightest diffuse feature in the Sgr A* complex region. Continuous monitoring of this molecular cloud and capturing its peak luminosity will tell us how luminous Sgr A* used to be a couple dozen years ago, which is essential to understand the activity cycle of supermassive black holes. This project is supported by NASA NuSTAR Guest Observation grant #80NSSC20K0035.
“It is amazing to have these molecular gas clouds as storytellers of past activities of the monster black hole in the center of our Galaxy,” says Zhang.
About the Annual Conference of the American Astronomical Society
The American Astronomical Society is the major organization of professional astronomers in North America, with a membership of 7,700 individuals with research and educational interests in astronomical sciences. The 239th meeting is the 2022 winter annual American Astronomical Society conference, which brings together the International astronomer community and shares the most recent discoveries and results in astronomy. Though the major meeting was canceled due to COVID situation, the press conference will take place virtually as planned.
Post Date: 01-11-2022