The Chemistry and Kinematics of Molecular Clouds near Sagittarius A*

John Lopez (University of New South Wales)

There is strong scientific evidence to show that Sagittarius A* (Sgr A*, in short hand form) is a supermassive black hole which is located at the center of our Milky Way galaxy. We have conducted a chemical and kinematical analysis of molecular clouds near this black hole. We selected an area of l = 0.47° (galactic longitude) x b = 0.2° (galactic latitude) within the Central Molecular Zone (CMZ), which encompasses the Galactic Center (GC).

A statistical analysis has been carried out on 21 regions, within our selected area, associated with the locations of molecular clouds close to the black hole. Concordantly, line abundance ratios were calculated for those regions. The results show that the molecular abundances are fairly consistent across all 21 regions, indicating that the gas is well mixed.

Furthermore, position velocity diagrams have been extracted from the radio data to analyse two molecular clouds close to Sgr A*, known as the 20 km/s and the 50 km/s clouds, as well as a connecting stream of molecular gas known as the Molecular Ridge. Our results show evidence that the 20 km/s cloud and the Molecular Ridge are part of one large elongated clumpy cloud with an extended velocity gradient across it (from 0 to 50 km/s) that spatially stretches as far as the 50 km/s cloud. This result is different to currently accepted models. Based on these results, we apply simple modelling to calculate appropriate timescales.

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