Max Planck Institute for Extraterrestrial Physics | 2020 Jul 27
For the first time, astronomers have observed a conveyor belt from the outskirts of a star-forming dense cloud directly depositing material near a pair of young forming stars. Scientists ... found that gas motions in the conveyor belt, dubbed a 'streamer', mainly obey the gravitational pull of the innermost part of the core, near the protostar pair. The streamer delivers a large amount of gas with chemicals recently produced in the mother cloud surrounding the star-forming region directly to the young protostars at the center of the core. These results are striking evidence that the large-scale environment around forming stars has an important influence on small-scale disk formation and evolution.
- Image of the “streamer” feeding chemically fresh material from a distance of about 10,500 AU to the proto-star at the centre of the image. The three images use different molecules as tracers, indicated in the top right corner, and all show the streamer in action. The colour coding is according to the integrated intensity of the signal. © MPE
In the general picture of star formation, a dense and cold region (called an envelope) forms inside a much larger and fluffier molecular cloud. Cloud material swirls and flows inwards towards the center of the envelope, where a future star will be born, the material becomes even more dense and flattens into a disk. Young protostars at the center of the disk feed and gain their mass directly from the disk. Now, for the very first time, a bright streamer of material connecting the outermost part of the envelope to the inner region where disks form has been observed in the Perseus Molecular Cloud. With the streamer helping to resupply the disk-scale region with more material as it is consumed by the binary system, the mother cloud can continue to help the young protostars and their protoplanetary disks to grow. ...
A Protostellar System Fed by a Streamer of 10,500 au Length ~ Jaime E. Pineda et al