Searching for the sources of violent explosions in space

Research Lives: Dr Sheila McBreen, associate professor, University College Dublin School of Physics

Dr Sheila McBreen: “We have physicists and engineers and mathematicians and it’s a student-led project, which is really exciting.”

Dr Sheila McBreen: “We have physicists and engineers and mathematicians and it’s a student-led project, which is really exciting.”

 

Sheila, you are interested in big explosions in space. Tell us more
“I work on gamma-ray bursts, which are big releases of energy. They usually happen because a star explodes, or when back holes collide. These bursts of gamma rays travel out from the site of the event across the Universe.”

How do you find out more about these violent explosions?
“We use detectors on board spacecraft out in space. The detectors monitor the levels of gamma ray signals, and if there is a sudden increase they can alert us on Earth. That means we can point ground-based telescopes towards the source of the gamma rays and find out more about where they came from. We have to move quickly though, because the gamma-ray bursts die away quickly, in the order of seconds or minutes.”

Why do you want look at them?
“The explosion that triggers a large gamma-ray burst typically lights up the galaxy where it happens, so if we look in that direction quickly, we have an opportunity to find out more about that galaxy.

The gamma rays tell us about which part of the sky is the best to find the source of the burst. But once the gamma-ray burst is gone, it is gone, and it is often the only chance we have to learn about host galaxy, when it is all lit up.”

What are you working on now?
“I am working with my colleague in UCD, Prof Lorraine Hanlon, on building gamma-ray detectors that can be sent into space. One of them will go aboard Ireland’s first satellite, Eirsat-1, which is being developed at UCD under the European Space Agency’s “Fly Your Satellite!” programme, and which is due to be delivered to ESA in 2020. We have already tested the gamma-ray detector by flying it on a balloon into space [from] Texas, and that worked really well.”

What do you find challenging about your work?
“You spend a lot of time looking for funding, and it is a competitive process, so not all project applications get funded and you have to take that on the chin and be resilient and try again. On the brighter side though, sometimes it works out well that one project doesn’t get funded, because you can take the feedback and revise the application and try again and it could be even better.”

What do you find rewarding about your work?
“Working with lots of different people. On the Eirsat-1 project in particular, we have physicists and engineers and mathematicians and it’s a student-led project, which is really exciting. I love teaching too, it’s gratifying to see the students learning and enjoying the courses.”

How do you take a break?
“In work, sometimes I sneak off to the library and find a quiet corner to read a few academic papers. At home, we have small kids so it’s a busy house, and I love to get out swimming when I can.”