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2020-10-09, 15:00: Dr. Claire Davies (University of Exeter)

Dr. Claire Davies

University of Exeter, UK

Disc-hosting young stellar objects at high angular resolution

Abstract: Directly observing the innermost astronomical units of the discs that surround stars as they form is crucial to our understanding of star and planet formation. Unless large-scale planetary migration is invoked, these regions are understood to be the main sites of planet formation. In addition, the structure and dynamics of the gas and dust in this region impacts stellar accretion and its associated outflows. For even the closest systems to the Earth, the inner disc regions subtend an angle on the order of 10s of milliarcseconds at most – a distance scale only accessible to optical long baseline interferometry. In this talk, I will present results from our surveys of young stellar objects with the CHARA Array from before and after the commissioning of our MIRC-X beam combiner. With the 330 m baselines of the CHARA Array and the sensitivity and baseline coverage of MIRC-X, we are spatially resolving the inner dust sublimation rims of the disks of these objects, revealing a range of grain growth efficiencies; the presence of optically thick material interior to the theoretical dust sublimation radius; and additional optically thick structures in the accretion-related outflows which contribute to the excess infrared continuum emission.