Science – High-mass stars are made of chaos, not dust disks

Madrid, 10 (Europe Press)

Observations with the ALMA telescope in Chile revealed that the high-mass stars form differently from their smaller siblings.

While young stars are often surrounded by an organized disk of dust and matter, the supply of matter to larger stars is a messy mess. The results have been presented in the Astrophysical Journal.

It is well known how tiny and tiny stars are created. It forms matter from the disk of gas and dust in a relatively orderly manner. Astronomers have already seen many of these dust disks around young, low-mass stars, but never around young, high-mass stars. This raised the question of whether large stars are born in the same way as young stars.

“Our findings now provide compelling evidence to demonstrate that the answer is ‘no,’ according to Ciriaco Goddi, affiliated with the ALMA Allegro Experience Center at Leiden University and with Radboud University in Nijmegen.

Goddie led a team that studied three young, high-mass stars in the W51 star formation region, about 17,000 light-years from Earth. The researchers were particularly looking for large, stable tablets that expelled jets of matter perpendicular to the surface of the disc. These discs should be visible with high-resolution ALMA telescopes.

“But instead of hard disks, we found that the accretion region of young, high-mass stars” appears to be a total mess, Judy explains.

The observation showed that filaments of gas were reaching young, high-mass stars from all directions. In addition, the researchers saw jets that indicate the possibility of small discs invisible to the telescope. Moreover, it appears that about a hundred years ago, the disk was wrapped around one of the three stars studied.

The researchers concluded that these young, high-mass stars, at least in their early years, are composed of matter coming from multiple directions and with irregular velocities. This differs for smaller stars, as there is a continuous flow of matter. Astronomers believe that such a multiple width of matter may be the reason why large, stable disks cannot be created.

“A disorganized flow model of this type was previously proposed, based on computer simulations. We now have the first observational evidence to support this model,” says Judy.