A joint research group of RIKEN and Chiba University used the ALMA telescope to observe a young "protoplanetary disk" in the process of observation. I found that interstellar dust may have begun to coalesce and grow.
There is a lot of gas around the newborn protostar, and the rotating gas settles in a radius where centrifugal force and gravity are balanced, forming a disk.This disk is called a protoplanetary disk because planets will be born in the future.
This time, the joint research group focused on this early disk and used the ALMA telescope constructed in the Atacama Desert in Chile to observe radio waves (bright lines) emitted by molecular gas and investigated its detailed structure.
As a result of high-sensitivity and high-resolution observations, it was found that the inclination of the rotation axis of the disk deviates between the inside and the outside.Such a structure is called a "warp structure" and indicates that the axis of rotation of the gas accreting from the outside to the protostar or disk changes over time.It has been known in the advanced protoplanetary disk with "accompaniment star", but it was the first time that it was discovered in the disk without companion star and in the early stage of formation like this time.
Furthermore, when the spatial change in the radio field intensity ratio of the two wavelengths of 1.3 mm and 0.9 mm was investigated, it was found that the radio field strength of 2 mm was relatively weak inside.The larger the size of the interstellar dust, the smaller the relative radio field intensity at shorter wavelengths, and this result indicates that the interstellar dust may have begun to grow on the inner disk.It may be a phenomenon that leads to the formation of structures in the disk, that is, the formation of planets, and it is an important finding for elucidating the origin of planets.
Paper information:[Nature] A Warped Disk around an Infant Protostar
