Tuesday 18 Oct 2016: Massive discs around massive stars
Dr. John Ilee - University of Cambridge
Physics, 4th Floor 14:00-15:00
The immediate circumstellar environments of massive young stellar objects (MYSOs) are incredibly difficult to observe directly. As such, the formation mechanisms of massive stars are poorly understood, with much information being obtained via indirect observational techniques. In this talk, I will give a brief overview of recent observational and theoretical work suggesting that Keplerian discs may play a large role in accreting matter on to MYSOs. In particular, I will discuss our recent work on a candidate young massive star G11.92—0.61 MM1 using the SMA and VLA. Our SMA observations show a bipolar outflow traced by CO J = 3–2 emission, and compact complex molecular emission toward the centre of MM1. Modelling of the gas kinematics suggest a structure undergoing rotation around the peak of the continuum emission, with a rotational profile can be well fit by a model of a Keplerian disc (with associated infall) enclosing a mass >30 solar masses. I will also discuss our recent work to examine the stability of these star-disc systems, which hints that they may actually be undergoing fragmentation, and our planned follow-up observations to confirm this hypothesis.