Speaker
Description
The Circumnuclear Disk (CND) is a ring of dense gas that lies within 2-5 parsecs of the Milky Way’s central supermassive black hole. The CND (M ~ 10,000 M_Sun) is the closest major reservoir of matter that could accrete onto the black hole, making it a crucial laboratory for understanding how central concentrations of gas drive inflows and correlate with central activity over cosmic time. We present preliminary maps of the CND with 1.5” (0.06 pc) resolution made from ALMA observations of SO, a high-density gas tracer. By analyzing these molecular line observations, we resolve individual gas clumps and filamentary features and can infer their relations to the ionized gas in Sgr A West, as well as possible interactions with two nearby giant molecular clouds. We perform a kinematic decomposition of the ALMA SO data using a newly developed Python implementation of the spectral line fitting algorithm SCOUSE. We fit the spectra with individual Gaussian profiles in order to model the full complexity of spectral lines in this source. This allows us to separate the CND into individual, kinematically-distinct components and measure where the gas is located, how fast it is moving, and follow its physical conditions as it gets closer to the black hole. The detailed analysis enabled by these observations will allow us to ultimately understand how similar structures arise in other galaxies and impact the physics of black hole growth.
| Talk Credit? | Yes |
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