The Accretion and Inner Disk of Pre-Main-Sequence Stars
5 November 2021 @ 7:30 pm - 9:30 pm GMT
An insight into some real astronomical research from a professional astronomer. Talk by Dr Justyn Campbell-White from the University of Dundee.
Low- and intermediate-mass stars acquire most of their mass in the protostellar phase, but accretion continues into the pre-main-sequence phase via a disk for a few million years. Accretion is a fundamentally important process, affecting disk stability/evolution, stellar rotation/activity, and planet formation/migration. The main observational challenge is probing the sub-au scales of the innermost disk, not yet possible for most of these stars, even via interferometry. Such young stars, however, possess a wealth of high-energy emission lines, revealing the nature of these accretion-related processes.
During my current position at the University of Dundee, I have developed the Python package, STAR-MELT, to automatically extract, identify, and fit emission lines, directly from the input spectral data. These lines can then be used to investigate the accretion activity and its temporal variability, allowing us to tomographically map the structures and inner disk of the stars.
In this talk, I will present an overview of our analysis method and the STAR-MELT package, along with results from our recently published paper that features analyses of three YSOs. We find that even with similar stellar parameters, the accretion processes and the final stages of star formation can be vastly different in terms of stability and nature.
Dr Justyn Campbell-White is a researcher at the University of Dundee in observational astrophysics. He is currently working on the final stages of star formation and the interaction between pre-main-sequence stars and their protoplanetary disks. Justyn obtained his PhD from the University of Kent in 2019, where his research focused on massive stars and the ionised hydrogen nebulae they create. He is also co-science lead for the HOYS (Hunting Outbursting Young Stars) citizen science project and will give a brief update on the status of this project during his talk.
We will also have the Sky in November from Alan Pickup.
For those watching online, here is the YouTube live video:
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Image: ALMA (ESO/NAOJ/NRAO)