Oral Presentation
Quantify the fragmentation of dense cores with ALMAGAL survey data
Presenter: Wei-An Chen (ASIAA & NTU)
Most stars form in clusters. However, the fundamental questions about the physics responsible for fragmenting molecular clumps into cores, which are the progenitors of stars, remain open. In order to study the impact of the local physical parameters (e.g. magnetic field, turbulent, gravity, evolutionary stage, etc.) on the fragmented dense cores, we first have to understand the origins of their morphology and determine the fragmentation status. Here, I present the analyses toward a sample of 649 ALMA field data from the ALMAGAL (ALMA Evolutionary study of High Mass Protocluster Formation in the Galaxy) survey using the algorithm of fragmentation number, which we develop in order to obtain statistical results. With the ALMAGAL data and some synthetic artificial images, we can discuss the properties of the fragmentation number and show that this quantity is mainly determined by core (e.g. flux, adjacent distance) and clump (e.g. aspect ratio) properties. Finally, our results show that the majority of the ALMAGAL clumps remain un-fragmented, while the rest of them are close to the “clustered” fragmentation.
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