Multi-scale energetics and fragmentation in star formation

At its core, star formation is the study of how diffuse gas in the large-scale interstellar medium becomes concentrated into small-scale dense structures which may then undergo local gravitational collapse to form stellar systems. This process is dominated by the complex interplay of three main processes - turbulence, magnetic fields and gravity - whose relative energetic importance is thought to change across spatial scales, and thus impact the fragmentation and formation of dense gas. However, the link between the energetics of these processes and dense gas structure formation has been difficult to study in a systematic manner due to the wide range of time-consuming observations necessary. In this talk I will present a new Taiwan-led SMA large-program, STREAMS, which combines interferometer and single-dish molecular line and dust polarisation observations to measure the energetics across two orders of magnitude in spatial scales for 23 different clumps. With such an extensive suite of observations, STREAMS will for the first time ever address the connection between energetics and fragmentation in a statistical manner with a robust, homogeneously observed and analysed sample. I will present our first results from two projects in STREAMS: a single-object observational study of the cloud SDC40, and a simulation study of the time evolution of clump energetics and fragmentation.

Onsite+Online(via webex):https://nckucc.webex.com/nckucc/j.php?MTID=mef75c2e6f82fac2722cb4519d21c155e