Midterm Colloquium by Marie Brekke – Niels Bohr Institute - University of Copenhagen

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Midterm Colloquium by Marie Brekke

Title: Origin of hot molecular gas emission in low-mass embedded protostars

Abstract: In the embedded stages of star formation, when the protostar is surrounded by an envelope of dust and gas, the protostar interacts strongly with the surrounding material. Such interactions results in hot molecular gas emission. Since the first observations of such emission in embedded low-mass protostars, the exact origin of the emission has been difficult to determine. The problem lies not in lack of theories, but rather in how to disentangle the effects of several heating mechanisms present. In this midterm colloquium I will introduce three main heating mechanisms that the ambient envelope material surrounding the protostar will experience. These are passive heating from the protostellar luminosity, ultraviolet radiation, and small scale shocks along the wall of the outflow cavity. I will then present results from Visser et al. (2011). Here they have modeled recent Herschel observations of three low-mass embedded protostars. In their model they have combined the three heating mechanism, with the aim of investigating the origin of the hot molecular gas emission, and determine the contributions of each mechanism.

I will round off the midterm colloquium by talking about how this relates to my own work on embedded protostars, which is mapping the interactions of jets with their protostellar envelopes.

Supervisors: Jes Jørgensen, NBI and Odysseas Dionatos, NBI