Credit: ALMA (ESO/NAOJ/NRAO), J.-E. Lee et al.

The gas distribution around the protostar IRAS 04239+2436, (left) ALMA observations of SO emissions, and (right) as reconstructed by numerical simulation on the ATERUI supercomputer. In the left panel, protostars A and B, shown in blue, represent radio waves from the dust surrounding the protostars. In protostar A, it is believed that there are two unresolved protostars. In the right panel, the positions of the three protostars are indicated by blue crosses. Credit: ALMA (ESO/NAOJ/NRAO), J.-E. Lee et al. New observations and simulations of the three spiral arms of matter that supply gas to three protostars forming in a triple star system have shed new light on the formation of multistellar systems. Most stars with masses similar to the Sun form in systems that are many with other stars. Therefore, understanding the formation of multiple star systems is crucial for a comprehensive theory of star formation. However, the complexity and lack of high-resolution, high-sensitivity data have left astronomers uncertain about the formation scenario. In particular, recent observations of protostars often report structures known as “streamers” of gas flux to protostars, but how these streamers form is still unknown. . An international team led by Jeong-Eun Lee, a professor at Seoul National University, used the Atacama Large Millimeter/submillimeter Array (ALMA) to observe the IRAS 04239+2436 protostar system located at a distance. 460 light years in the constellation Taurus. The team found that the emissions of sulfur monoxide (SO) molecules trace three spiral arms around three protostars forming in the system. Their paper was published in the Astrophysical Journal. The supercomputer “ATERUI” simulates the formation of many stars. The film shows that a number of protostars are born in a turbulent filamentous gas cloud, and that they excite the spiral arms and disturb the surrounding gas in their orbits. Credits: Tomoaki Matsumoto, Takaaki Takeda, Project 4D2U, NAOJ Compare that with simulations shown by Tomoaki Matsumoto, a professor at Hosei University, using the ATERUI and ATERUI II supercomputers at the National Center for Computational Astrophysics of the National Astronomical Observatory of Japan (NAOJ) that the three spiral arms are the streamers that supply the three protostars. For the first time, a combination of observations and simulations has revealed how streamers are generated and contribute to the growth of central protostars.

Source:  Jeong-Eun Lee et al, Triple Spiral Arms of a Triple Protostar System Imaged in Molecular Lines, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/acdd5b