Disruption of a massive molecular cloud by a supernova in the Galactic Centre 

Left panel: HNCO (4-3) peak intensity map from ACES towards the M0.8-0.2 Ring. The dotted white circles show the approximate extent of the ring-like structure. Right panel: Multi-wavelength view of part of the CMZ, showing the location of the M0.8-0.2 Ring, indicated by the dotted white circles.

The Central Molecular Zone (CMZ) is the most extreme environment in the Milky Way. Located in the inner few hundred parsecs of our galaxy, the CMZ exhibits turbulent motions, magnetic field strengths, gas densities, pressures, and temperatures orders of magnitude greater than those measured in our local solar neighbourhood. The gas dynamics within the CMZ are similarly extreme, with strong gravitational shear capable of stretching molecular clouds. The extreme nature of the CMZ makes it the perfect laboratory to test theories of star formation in environments that differ from our galactic disc. The ALMA Central Molecular Zone Exploration Survey (ACES) provides an unprecedented, high-resolution view of the gas at the centre of our galaxy, seeking to better our understanding of this highly complex region.

Nonhebel et. al (2024) presents some of the first results from the ACES collaboration, exploring the morphology and kinematics of a ring-shaped molecular cloud with the CMZ. The M0.8-0.2 Ring is a highly energetic and massive molecular cloud with a striking 'whirlpool-esque' morphology, as revealed by ACES observations of the HNCO (4-3) line. The authors explore potential theories behind the unique morphology of the molecular cloud, including the possible roles of stellar feedback, cloud-cloud collisions, and large-scale dynamics. Nonhebel et. al (2024) concludes that the most likely explanation behind the M0.8-0.2 Ring is an explosion of an abnormally luminous supernova, or 'hypernova', embedded deep within a molecular cloud.

Contributed by Mairi Nonhebel

ALMA poll of the month

Results from October's poll, "Have you considered submitting a joint observatory proposal?"