Disc winds in the evolution of planetary systems – Prof Cathie Clarke

This talk was part of the UH Centre for Astrophysics Research (CAR) 2022-2023 seminar series. For the ongoing programme, please see: https://www.herts.ac.uk/research/cent...

Date: 3 May 2023
Speaker: Prof Cathie Clarke – University of Cambridge
Title: Disc winds and environment: their role in the evolution of planetary systems

Abstract: In recent years, there has been considerable interest in the role of mass loss from protoplanetary discs. Such winds remove mass and entrained dust from the disc and thus erode the reservoir of material available for planet formation. In addition, in cases where the wind is magnetically driven, angular momentum extraction from the disc may drive the process of accretion onto the star.

In the first part of the talk, I will focus on winds that are internally driven. I will show how new analytical models for thermally driven winds from discs can allow ready comparison with line kinematic data and how spectroastrometric and JWST spectro-imaging data can constrain wind mass loss rates and morphology. I also describe constraints derived from modelling haloes of scattered light emission seen by HST in edge-on discs. While not explicitly modelling MHD winds, I will also discuss the prospects for unravelling the driving mechanism for such winds.

In the second part of the talk, I will describe how the dispersal of protoplanetary discs can be driven by environmental effects. I will show, using our models for disc photoevaporation based on the FUV emission from neighbouring massive stars, that photoevaporation is likely to overwhelmingly dominate the role of star-disc encounters in dispersing disc material in dense clusters.

Finally, I introduce recent investigations of a further environmental effect on mature exoplanetary systems based on the fate of planets in globular clusters. These studies lead to the intriguing possibility that abundance variations in globular clusters may result from the ingestion of gas giant planets.