An international research team has made the first ever detection of a baby star being fed with a dusty “hamburger” – dusty accretion disk – with the Atacama Large Millimeter/submillimeter Array (ALMA).
This new image not only confirms the formation of an accretion disk around a very young protostar, but also poses a big challenge on some current theories of disk formation.
Jet and disk in the HH 212 protostellar system: (a) A composite image for the jet in different molecules, produced by combining the images from the Very Large Telescope (McCaughrean et al. 2002) and ALMA (Lee et al. 2015). Orange image around the center shows the dusty envelope+disk at submillimeter wavelength obtained with ALMA at 200 AU resolution. (b) A zoom-in to the very center for the dusty disk at 8 AU resolution. Asterisks mark the possible position of the central protostar. A dark lane is seen in the equator, causing the disk to appear as a “hamburger”. A size scale of our solar system is shown in the lower right corner for size comparison. (c) An accretion disk model that reproduces the observed dust emission in the disk. Credit: ALMA (ESO/NAOJ/NRAO)/Lee et al.An accretion disk model that reproduces the observed disk emission. (a) The accretion disk model with the disk surface temperature. (b) The image created based on the model, is roughly the same as the observed image of the disk. Credit: Lee et al. via Alma ObservatoryA cartoon showing an accretion disk feeding the central protostar and jets coming out from it. Credit: Yin-Chih Tsai/ASIAA. via Alma Observatory