An international team of researchers, using the Atacama Large Millimeter/submillimeter Array (ALMA), has made significant discoveries about the formation of multiple stars. Led by Professor Jeong-Eun Lee from the University of Seoul, the team observed the triple protostar system IRAS 04239+2436 and detected radio waves emitted by sulfur monoxide (SO) molecules, indicating the presence of shockwaves. They also discovered that the distribution of SO molecules formed three large spiral arms, which act as “streams” supplying material to the protostars.

The formation of multiple stars is still not well understood, with various scenarios proposed. To gain a better understanding, high-resolution observations of the moment when multiple protostars are born are necessary. Recent observations have reported the presence of gas structures called “streams” flowing towards the protostars. However, the origin of these streams has remained unclear.

Observations of the triple protostar system with ALMA revealed large spiral arms formed by the distribution of SO molecules. Through comparisons with numerical simulations, the researchers found that these spiral arms are indeed streams supplying gas to the protostars. This discovery provides information about the formation of multiple stars and confirms the ability of numerical simulations to explain the origin of these streams.

Previously, two scenarios for the formation of multiple stars had been proposed: the “turbulent fragmentation scenario” and the “disk fragmentation scenario.” Observations of the triple protostar system support a hybrid scenario where the star formation process begins as a turbulent cloud of gas, similar to the turbulent fragmentation scenario.

This study emphasizes the importance of detailed observations and simulations in understanding the complex structures and dynamics involved in the formation of multiple stars. The findings contribute to the development of a comprehensive theory of stellar formation and provide valuable insights into the formation of multiple stellar systems.

– Atacama Large Millimeter/submillimeter Array (ALMA)
– University of Seoul
– Hosei University
– National Astronomical Observatory of Japan (NAOJ)