Formation of young stellar objects within molecular clouds
Stellar systems, like our solar system, are formed within dense molecular clouds in the interstellar medium. In a large-scale (molecular cloud-scale) scenario, several environmental conditions, like hub filament formation, H II regions, and edge-dominated filamentary collapse, can influence the formation of stars or star clusters. Although the dominant mechanisms are not observationally constrained. In a smaller-scale (protostellar core scale) scenario, while a dense molecular core undergoes gravitational collapse, a disk-jet system is formed naturally to conserve angular momentum. The jet appears from the protostellar disk surface and removes excess angular momentum, therefore, playing a vital role in the growth of the central core, the formation and evolution of the circumstellar disk, the chemical composition of the disk and emerging planetesimals within it. However, the jet launching zones and the impact of accretion bursts on the emerging planets are not well studied observationally due to a lack of very high-resolution observations.
In this seminar, I shall present the formation and evolution scenario of the dense core, especially the (1) dominant mechanisms of molecular cloud collapse (2) the launching mechanisms and morphological changes of the protostellar jet (3) the impact of accretion outbursts in the chemical composition of the emerging planetesimals, First, I shall discuss the dominant environmental effects of protostar formation in molecular clouds with our multiwavelength observations. Then I shall talk about our recent results on protostellar jet/outflow from the high spatial resolution and high sensitivity observations with Atacama Large Millimeter/submillimeter Array (ALMA), which is currently the largest radio interferometry array on Earth. In particular, I shall probe the dominant mechanism of jet launching, whether the jet launches from the inner disk (i.e., X-wind) or a more extended disk region (i.e., disk-wind). Finally, I shall describe the possible connection of the jet with the accretion burst and formation of complex organic molecules (COMs) within the disk, which would be the chemical composition of emerging planetesimals.