Stars develop by the gravitational contraction of clouds of gas in space and can possess several masses. Enormous stars, along with various other stars, might develop a large star cluster (a group of over 10,000 stars).
The development of such a star cluster needs the quick packing of huge amounts of gas and other materials into a compact space. However, the mechanism by which this takes place is yet to be explained.
Under the guidance of Associate Professor Kengo Tachihara and Emeritus Professor Yasuo Fukui of Nagoya University, a research group concentrated on a hypothesis in which several gas clouds tend to clash, thereby enabling them to get collected in an efficient manner and thus developing into a star cluster.
To confirm this hypothesis, the research group, together with scientists from Osaka Prefecture University and the National Astronomical Observatory of Japan, carried out observational studies of a huge amount of data acquired by research performed over a decade, including theoretical studies of numerical simulations with the data.
They discovered that collisions of gas clouds hovering in space do, indeed, trigger the origin of a star cluster.
The researchers noticed that several collisions of gas clouds in the Milky Way Galaxy and also in other galaxies indicate that such collisions are a global phenomenon.
From this point of view, there is a high chance that the Milky Way Galaxy collided with other galaxies shortly following its birth, which led the gas clouds in the galaxies to collide often, leading to the development of several globular clusters (groups of over one million stars).
The study results have contributed to better insights into the formation of huge stars and the origin of globular clusters.
The study includes a collection of 20 original papers depending on detailed verifications of separate astronomical bodies, as well as a review paper outlining the latest insights into star formation by collisions of gas clouds.
Fukui, Y., et al. (2021) Cloud–cloud collisions and triggered star formation. Publications of the Astronomical Society of Japan. doi.org/10.1093/pasj/psaa103.