Mar 8 2019

Paying It Forward to the Next Generation of Computational Researchers

Professor Carol Jones, Professor, Physics and Astronomy Department, Associate Dean of Faculty/Staff Relations for the Faculty of Science, Western University

In conversation with Professor Carol Jones, Professor, Physics and Astronomy Department, Associate Dean of Faculty/Staff Relations for the Faculty of Science, Western University

 

When did you first become interested in Physics and Astronomy? Did you always know this was what you wanted to do?

Most people are fascinated by the night sky and are captivated by the big puzzles the universe presents. I was too, but it wasn’t until much later in life that I took a real interest in astronomy. I always liked math and physics and enjoyed these subjects through school. I happened to take an astronomy course as an option during my undergrad and realized that I could apply all the tools I learned in math and physics to this field of research to understand more. That inspired me.

I find astronomy very fascinating since it helps you understand the big picture and explores important questions. For example, is there life elsewhere in the universe among other things.

 Can you tell us about your field of research and the impact it has?

Our galaxy, the Milky Way, is in the form of a disk and there are many other examples of astrophysical disks. Studying disk systems helps us understand other many processes that operate in the physical universe. I study disks surrounding massive stars, particularly B-emission stars, that exhibit emission lines in their spectra due to the interaction of starlight with the disk material.

These stars spin fast which helps to release material from the star to form a disk. However, despite decades of study, we don’t know exactly how the disk forms, and this is the major unsolved puzzle in this field. Also, the interplay between rapid stellar rotation and stellar evolution, especially for the massive stars, is not well understood. We currently don’t understand all aspects of disk physics and understanding this type of astrophysical disk helps us understand other types of disks in nature and will also provide key information about stellar evolution.

 

So based on our understanding, getting to know more about disk systems and their formation is crucial to understanding the physics of the universe because they might give us answers as to how other bodies form in the universe?

Yes, the stars I study eventually blow up in supernova explosions which enriches their surroundings with elements heavier than iron.  These elements, in turn, may become part of a future generation of stars. Also, these massive stars, through their strong stellar winds during their lifetimes and when they blow up as a supernova at the end of their lives, play a significant role in the evolution of their parent galaxies. For example, the actual supernova might happen to trigger star formation somewhere nearby.

 

What role does advanced research computing (ARC) play in your research?

My group is tackling major questions in this field of research.  We are not sure how the material comes off the star and into the disk. Rapid rotation certainly helps, but there must be other processes operating to cause the material to be launched from the surface of the star such as stellar pulsations or a gravitational interaction with an orbiting companion star. We don’t know if the material is released continuously or whether it comes off in bursts.

Thanks to the powerful computational power we have now in Ontario, we can model these systems of stars and the disks to understand them better. ARC gives us the computational tools we need to build realistic models and SHARCNET provides us with all the resources we need to do so. For example, we have developed 3D codes that can simulate material launched from the stellar surface, allowing us to follow changes in disk density with time, for both isolated systems and stars with companions. Another 3D code, called a radiative transfer code, helps us predict the signatures in the light at different wavelengths and make theoretical images in the plane of the sky. We constrain our predictions by comparison to real observations from world-class observatories.

Do you also train students to use advanced computing, and if so, have you seen that it impacts their future research?

Student training is really important, and my group has had the opportunity to publish research accomplished using advanced computing techniques.

The skills my students gain are valuable. Students have opportunities for careers in academia, if they choose, and also based on their computing skills, imaging techniques, and experience working with large data sets have opportunities for work in industry. My students while working on fundamental research are acquiring skills that are relevant to a wide variety of industrial applications.

My work would not be possible without the computational facilities available. For example, one code that I use takes about 24 hours to run on 24 processors. The output from these simulations are huge binary files. We analyze our results, make images of our predictions and compare them to real observations. It’s incredible work!