ISAS Space Science Colloquium & Space Science Seminar
The formation mechanism of high-mass stars and clusters: A dominant role of cloud-cloud collisions
Yasuo FUKUI（福井 康雄）
Star formation is a fundamental process which determines the evolution of the Universe. The mechanism of low-mass star formation was established around 1990, 20 years after the discovery of the interstellar molecular clouds where stars form. It was a difficult task to unveil the mechanism of high-mass star formation which requires unusually strong mass concentration in the interstellar space.
Recent studies, both observational and theoretical, have shown that high-mass stars form under triggering by cloud-cloud collisions which are able to collect large mass in a short time scale. Up to now, more than 70 regions of high-mass star/cluster formation were revealed to show signatures of colliding clouds. These include very massive clusters in the Antennae galaxies, the super star cluster R136 in the Large Magellanic Cloud, and HII regions in Orion. A statistical analysis allowed us to derive a strong correlation between the cluster mass and the ambient pressure. The relationship is used to predict the conditions for the formation of the globulars in the early universe. I summarize the essence of these findings and discuss the future prospects.
Place: Bldg. A 2F Conf. hall（1236）/ A棟２階会議場（1236号室）