Colloquium (Mark Gorski): A sub-pc Glimpse into The Cool Molecular Gas Around Sgr A*

Event Details

Speaker: Dr Mark Gorski, Northwestern University

Place: Natural Sciences Building, Room 112 


In the last 50 years, significant progress has been made in understanding how supermassive black holes accrete their gas from megaparsec scales down to the accretion disk (~10pc scales). However, our understanding still lacks the final stages of accretion. Hiding behind the dust lanes of the Milky Way lies our best chance to study black hole physics, accretion, feeding, and feedback, Sagittarius A* (Sgr A*).  Here, I present a comprehensive view of the molecular gas surrounding Sgr A* from sub-light-year to parsec scales. I present the first ever 0.01 pc (0.03 ly) resolution image of the CO(2-1) line, tracing cool (~100 K) molecular gas. The image is two orders of magnitude improved in sensitivity and resolution compared to the previous most-sensitive interferometric maps of the cool molecular gas. Through comparison with multi-wavelength observations spanning radio to X-ray wavelengths, this ongoing study reveals several key findings. First, we reveal a large conical clearing indicative of an outflow. Second, we calculate the CO-to-H2 conversion factor in this crucial environment. Finally, I reveal indications of molecular gas interacting with the supermassive black hole. This study provides the clearest view yet of how molecular gas feeds Sgr A*.