23 Febbraio 2022, ore 11:00
Title: Establishing a timeline for the high-mass star formation process
Speaker: Dr. Giovanni Sabatini da INAF-IRA
Abstract: Despite the efforts made in recent years to understand the formation of massive stars (M>8-10 M⊙), some fundamental questions remain unanswered. One of these is related to the timescales of the different evolutionary phases of their formation process, which are difficult to constrain, since high mass stars precursors remain deeply embedded in their parental clumps for almost their entire formation and early evolution. Luckily, the chemical composition of the hosting clump is heavily influenced by the changes in density and temperature that occur during the formation of a massive young stellar object. Therefore, specific chemical species can be used as a powerful chemical clock to probe the evolutionary stage of the system. In this talk, I will compare the observations of several chemical clocks in a large sample of massive clumps in different evolutionary stages with accurate time-dependent chemical models that we developed. Doing so, we derived the timescale for different evolutionary phases and we are able to propose a timeline for the entire massive star formation process. In addition, I will discuss the reliability of crucial chemical clocks, both for the early and the late stages, confirming that chemistry is a powerful tool to establish a timeline for the high-mass star formation process.