Back to Volume
Paper: Twins at Heart: The Centres of M83 and the Milky Way as Opposite Extremes of a Common Star Formation Cycle
Volume: 528, New Horizons in Galactic Center Astronomy and Beyond
Page: 295
Authors: Callanan, D.; Longmore, S. N.
Abstract: The environmental properties which control star formation are observed to be the same within observational constraints in the nucleus of M83 and the Milky Way. Given this similarity, the reason why M83's nuclear star formation rate (SFR) is an order of magnitude greater than the same region of the Milky Way is an unanswered puzzle. Using ALMA observations of HCN (1–0) and HCO+ (1–0), we derived the dense gas properties on the scale of individual molecular clouds in M83's nucleus, and compared these with cloud properties in the nucleus of the Milky Way. We find that the cloud-scale gas distribution and gas properties in both nuclei are similar, and a common mechanism may instigate star formation in both circumnuclear gas rings. Given these conditions, it is most likely that the order of magnitude difference in SFR is caused by time variable star formation activity. While the centre of the Milky Way is currently at a minima within this time variability, M83's SFR was an order of magnitude larger 5–7 Myr ago. This time variability in star formation and feedback cycles means that modeling must avoid averaging over large timescales and that statistical samples of galaxies are required to properly compare the multi-scale processes controlling star formation cycles in galactic nuclei.
Back to Volume