Dr Charissa Button
A PhD astrophysics graduate ready to lend a hand to SKA
Dr Charissa Button is a big proponent of the Square Kilometre (SKA), which she cannot wait to become a part of. She recently made history by becoming the University of Pretoria (UP)’s first PhD graduate in astrophysics.
The SKA is by far one of the world’s biggest radio telescope infrastructure projects that will not only create huge investment and economic opportunities for South Africa, but it will also help develop a pool of young and brightest scientists in Africa. Once completed, the SKA will leverage the capability of radio astronomy to provide the highest-resolution images of the Milky Way galaxy with the least radio interference.
High-profile global initiatives
Dr Button says she is excited to grow astronomy at UP and the country especially as SKA and MeerKAT are such vital and high-profile global initiatives in which the university is involved. She first became interested in pursuing post-graduate studies in radio astronomy because of its ability to explore and interrogate fundamental questions in physics including the nature and effects of dark matter, and the expansion of the universe.
The outer discs of spiral galaxies
“During my studies in radio astronomy, I became interested in the vast array of physical processes that contribute to galaxy formation and evolution. This has included the neutral atomic hydrogen gas (HI) found in the outer discs of spiral galaxies, as well as hydroxyl megamasers (OHM’s), typically found in the inner regions of merging galaxies, which both provide valuable information on the star formation taking place in these galaxies. Due to the intrinsic faintness of these emission lines, studies of them have historically been limited to the nearby universe,” explains Dr Button.
Finding gravitational lensing
Dr Button’s PhD programme focused on exploring gravitational lensing as an approach to probe the more distance universe. “My thesis explored methods for finding gravitationally lensed HI sources and OHM’s in upcoming SKA surveys, which will significantly increase their scientific yield. Gravitational lensing, which Einstein predicted in his general theory of relativity, arises when a massive object, like a galaxy, lying in the foreground of a more distant galaxy, bends the light rays from the distant galaxy (like a raindrop on a window), thereby amplifying the signal of the distant galaxy that would otherwise be too faint to detect with current instruments,” says Dr Button.
Influence from a decorated academic
Although Dr Button has been pursuing astronomy as part of her postgraduate studies, it was Professor Roger Deane who influenced her decision. Professor Deane is a respected figure within the astronomy community. He is credited for setting up UP’s Radio Astronomy Research Group in 2018 and currently serves as an Extraordinary Professor in the Department of Physics in the Faculty of Natural and Agricultural Sciences and as SARChI SKA Chair in Radio Astronomy at the University of the Witwatersrand. This is why Dr Button didn’t hesitate to enroll for her a postgraduate degree in astronomy.
Power of smart algorithms
Commenting on Dr Button’s recent achievement as a scientist in astronomy, Professor Deane said: “Dr Button’s PhD is an excellent example of how a bright young mind can use the power of smart algorithms and big data to make new important cosmic discoveries with next-generation telescopes like the Square Kilometre Array. I’m excited that we’ll soon be able to test her predictions with the SKA, building on a strong foundation of experience with MeerKAT,” says Professor Deane.
Forging partnership with international researchers
Dr Button says she would build on international partnerships forged during her PhD studies with the Universities of Oxford and Western Australia as she pursues a broader research portfolio. She says UP’s membership of the Inter-University Institute for Data-Intensive Astronomy has facilitated such partnerships and networks.
Her full-time postgraduate studies were funded by the South African Radio Astronomy Observatory (SARAO). She is currently a SARAO postdoctoral fellow at UP. As part of her studies she made presentations on her research at various conferences internationally, such as in Bristol in the UK and locally. This gave her a valuable platform to engage and interact with the broader international radio astronomy community.
Dr Button is the face of a new generation of the brightest, innovative and enterprising minds within the science field. Her passion for astronomy would no doubt go a long way in motivating more young girls.
