View to a cosmic thrill
A visit to busy UCD astrophysicists followed the most powerful gamma-ray burst ever seen
Kevin Courtney with Prof Lorraine Hanlon and Dr Sheila McBreen, of the Space Science Group, in UCD, looking at an XMM neutron space craft model. Photograph: Dara Mac Dónaill / The Irish Times
A portrait of Frank Heffernan, a technician in the School of Physics, by Emer O’Boyle
It’s the cosmic question that has puzzled minds since time began: what do astrophysicists do all day? Somehow you imagine the typical day of an astrophysicist would be somewhat elevated above the humdrum daily lives of the rest of us earthlings. They wouldn’t be bothering with such earthbound concepts as committee meetings, funding presentations or the specific gravity of the canteen coffee, would they?
I’ve been dispatched to the College of Physics in UCD to spend the day with Prof Lorraine Hanlon and her team, and maybe even join in with their work.
Prof Hanlon studies gamma ray bursts – in fact, she’s one of the world’s leading authorities on GRBs, as they call them round here. So, I’ll be working with deadly gamma rays – if I suddenly turn a bright shade of chartreuse, or develop the uncanny ability to shoot heat-rays out of my eyes, well, it’s worth it in the name of science.
Unbearable lightness of gamma rays
I needn’t worry – the gamma ray bursts Prof Hanlon and her team study emanate from so far away, they wouldn’t make a gnat glow. That doesn’t make them any less powerful – in fact, gamma ray bursts are the highest-energy phenomena in the universe.
When a very large star collapses, it releases a super-concentrated burst of gamma rays which can be detected by earth-orbiting telescopes such as Nasa’s Fermi Large Area Telescope. These events are happening billions of light-years away; if one were to happen within, say, 3,500 light-years of earth, it would strip away our ozone layer and leave us all to fry.
A star explodes somewhere in the visible universe roughly once a day, so I’m hoping one will go kaboom sometime during my shift with the stargazers – though not within sizzling distance. If you’re not reading this, however, we may already be cosmic fondue.
Turns out I’ve arrived at a good time. Just four days previously, the most powerful gamma-ray burst ever seen was detected by Nasa’s Fermi and Swift space telescopes. Not only was it the most high-energy GRB ever seen, it also had the longest duration, remaining visible as gamma-ray light for more than half a day. GRB130427A (named for the date of its detection) was only about 3.6 billion light years away – pretty close in astronomical terms. The GRB has long since tailed off, but the buzz can still be felt through the entire astrophysics community.
Prof Hanlon, a cheerful, unboffinlike figure, greets me at the Science Centre. In the common-room, I meet some of her team, including Sheila McBreen, Suzanne Foley, Alexei Ulyanov and Martin Topinka. Everyone looks surprisingly normal – think I expected to meet the cast of The Big Bang Theory. The conversation, however, is anything but normal. Where other canteens would ring with chat about last night’s telly or Kim Kardashian’s chihuahua, the topics of conversation here include multiverses, bosons and dark matter.
We visit one of the labs, where Hanlon and her team are developing a gamma ray detector module for use on one of the European Space Agency’s (ESA) orbiting telescopes. This kind of technological development is vital to ensure continued funding for Hanlon’s research.
Along the way, we stop at an impressive display: a 1:4 scale model of the XMM-Newton orbiting telescope, donated by the European Space Agency, of which Ireland has been a member since 1975.
I spend the next couple of hours ‘working’ with some of Hanlon’s researchers, which entails looking over their shoulders while they do some very complicated-looking stuff on their computers. Suzanne Foley is completing a paper on her research into terrestrial gamma-ray flashes, or TGFs. That’s right. Gamma-rays from earth. At first, no one could work out where these faint gamma-ray bursts were coming from. Then they found the source: thunderstorms. And you were worried about getting hit by lightning.