Navigating a Cosmic Maelstrom with Sub-Parsec Observations of Cool Gas Around Our Central Supermassive Black Hole

Mark Gorski, PhD

Hiding behind the dust lanes of the Milky Way lives our closest supermassive black hole (Sagittarius A* or Sgr A*). It is hailed as both our best hope to study black hole physics, accretion, feeding, and feedback, and as too complex a region to completely understand. The absence of any signatures of an active outflow and the spin orientation of the black hole are some of the longest-standing puzzles. Every simulation predicts an outflow from Sgr A*, but observational evidence remains elusive. Here, for the first time, we present a complete picture of accretion flow around the Milky Way's Galactic Center black hole from sub-lightyear to parsec scales. Using a novel source subtraction technique to remove short-timescale variability of Sgr A*, we reveal the molecular gas flows around our own supermassive black hole. The resulting image is two orders of magnitude improved in sensitivity and resolution compared to the previous most-sensitive interferometric maps. We present the first ever 0.01 pc (0.03 ly) resolution image of the CO(2-1) line, tracing cool ~100 K molecular gas. Comparing with multi-wavelength observations from radio to x-rays, we reveal a complete picture of the environment of Sgr A*. A large 1.5 pc outflow with an opening angle of about 45 degrees is visible as a conical clearing in the molecular flow, illuminating the missing outflow.