ALMA | NRAO | 2021 Apr 27
A team of astronomers using the Atacama Large Millimeter / submillimeter Array (ALMA) has taken a big step toward answering a longstanding question — do stars much more massive than the Sun form in the same way as their smaller siblings?ALMA images of the chaotic scene around massive young protostars, (left: W51e2e,
center: W51e8, right: W51north). Grey shows dust close to the star, while the red and
blue indicate material in the jets moving rapidly outward from the star. Red shows
material moving away from Earth and blue material moving toward Earth.
Credit: Goddi, Ginsburg, et al., Sophia Dagnello, NRAO/AUI/NSF
Credit: Goddi, Ginsburg, et al., S. Dagnello, B. Saxton, NRAO/AUI/NSF
Young, still-forming stars similar in mass to the Sun are observed gaining material from their surrounding clouds of gas and dust in a relatively orderly manner. The incoming material forms a disk orbiting the young star and that disk feeds the star at a pace it can digest. Condensations of material within the disk form planets that will remain after the star’s growth process is complete.
The disks are commonly seen around young low-mass stars, but have not been found around much more massive stars in their forming stages. Astronomers questioned whether the process for the larger stars is simply a scaled-up version of that for the smaller ones.
“Our ALMA observations now provide compelling evidence that the answer is no,” said Ciriaco Goddi, of Radboud University Nijmegen in the Netherlands.
Goddi led a team that used ALMA to study three high-mass, very young stars in a star-forming region called W51, about 17,000 light-years from Earth. They used ALMA when its antennas were spread apart to their farthest extent, providing resolving power capable of making images 10 times sharper than previous studies of such objects. ...
Multidirectional Mass Accretion and Collimated Outflows on Scales
of 100–2000 au in Early Stages of High-Mass Protostars ~ Ciriaco Goddi et al