Thursday 08 Dec 2016: Toward Galactic View of Star Formation
Prof. Shu-ichiro Inutsuka - Nagoya University
Physics, 4th Floor 11:00-12:00
Abstract: We propose a unified picture of star formation in the Galaxy. Recent high-resolution magneto-hydrodynamical simulations of two-fluid dynamics with cooling/heating and thermal conduction have shown that the formation of molecular clouds requires multiple episodes of supersonic compression. This finding enables us to create a new scenario of molecular cloud formation as the interacting shells or bubbles in galactic scale, which explains many observational aspects of interstellar medium such cloud-to-cloud velocity dispersions, accelerating star formation, and very low star formation efficiencies. We estimate the ensemble-averaged growth rate of individual molecular clouds, and predict the associated cloud mass function. The recent claim of cloud-cloud collisions as a mechanism for forming massive stars and star clusters can be naturally accommodated in this scenario. This explains why massive stars formed in cloud-cloud collisions follows the power-law slope of the mass function of molecular cloud cores repeatedly found in low-mass star forming regions.