Persistent time lags in light curves of Sagittarius A*: evidence of outflow

Understand

The compact radio source at the center of our Galaxy, Sagittarius A* (Sgr A*), is the subject of intensive study as it provides a close-up view of an accreting supermassive black hole.

• Sgr A* provides us with a prototype of a low-luminosity active galactic nucleus (LLAGN), but interstellar scattering and the resolution limits of our instruments have limited our understanding of the emission sites in its inner accretion flow.
• The temporal variability of Sgr A* can help us understand whether we see a plasma outflow or inflow in the region close to the black hole.
• In this work, we look at a comprehensive set of multi-epoch data recorded with the Karl G.