On the hunt for gravitational wave sources in space

9 Mar 2018

Irish Research Council scholar Lána Salmon. Image: Vincent Hoban

Lána Salmon is actively seeking gravitational wave sources in space and helping to build Ireland’s first satellite. She spoke to Dr Claire O’Connell.

When Lána Salmon started her PhD in astrophysics in University College Dublin (UCD) last year, she took a step into the unknown.

Her project was to develop better ways for robotic telescopes to find sources of gravitational waves, massive ripples of energy cause by objects such as stars or black holes colliding.

Future Human

By the time she started her studies, gravitational waves were already garnering attention. In 2015, the LIGO and VIRGO international consortia detected the waveform of two black holes merging, and gravitational waves became one of the hottest topics in astrophysics. That discovery made international news when the findings were announced the following February.

Spectacular timing

For her PhD, which is funded by the Irish Research Council, Salmon wanted to help ‘optical’ telescopes to home in on the sources of these gravitational waves.

When she began, there was the tiny but rather important issue that no one had yet detected an optical signal related to gravitational waves – but that was about to change.

“When I wrote the proposal for the work with my PhD supervisors [Prof Lorraine Hanlon and Dr Antonio Martin-Carrillo at UCD], they warned me that we might not be able to see gravitational waves with these telescopes,” she said.

“But then, three days after I started, the optical counterpart to gravitational waves was detected.”

This spectacularly timed event led to Salmon working with her supervisors and UCD physicist Dr Morgan Fraser with the ePESSTO collaboration on a paper in the prestigious journal Nature – not a bad start to a PhD.

So, what does she do today?

“When LIGO and VIRGO detect gravitational wave sources, they send out information about the general area where the source is, so that telescopes can look at it, but it is a huge area of sky. Part of my PhD is to write code for the UCD Watcher telescope to help it find the source,” she said.

“The events that cause gravitational waves are often near galaxies, so I look for the galaxies in the area of sky and try and calculate the probability of the merger happening in that locality.”

Satellite communications

The other half of Salmon’s PhD is on EIRSAT-1, Ireland’s first satellite, which is being led by the UCD Space Science Group.

Due to launch in 2020, the satellite will detect gamma-rays emitted by large collisions in the universe. It will perform experiments on a high-tech spacecraft coating developed by Irish company Enbio, and it will test out control algorithms developed by Dr David McKeown in UCD to stabilise the satellite and reduce vibrations that could otherwise damage equipment.

Salmon initially started in outreach on the project and she is now also in charge of building the ground station to transfer data between the ground and the satellite. “It will be a tough couple of years and it’s all hands on deck here; we are encouraging final-year and postgrad students of maths and computers and physics in UCD to get involved,” she said.

Salmon’s passion for science and outreach is obvious – she has translated many space resources into Irish – and it was science communication and public engagement that sparked her interest in the first place.

A visit to Kennedy Space Center with her family when she was 10 years old set her sights on the sky, and hearing Prof Brian Cox describing the world through maths and physics encouraged her to study those subjects.

“Communication is integral for scientists. I think we have to get out there and engage with people about what we do,” she said.

PhD student Lána Salmon admiring the Milky Way at Teide Observatory in Tenerife during an undergraduate field trip. Image: Lána Salmon/Dr Antonio Martin-Carrillo

Mountain observatory

This weekend, Salmon will be practising what she preaches as she accompanies a group of 11 undergraduates to Tenerife, where they will spend seven nights using world-class telescopes – the IAC80 and Carlos Sánchez telescopes – on top of Mount Teide.

They will share the experience through live streams and social media (see #UCDTeide18 and takeovers on the UCD Instagram account).

“The students get to choose any object – such as galaxies, clusters, exoplanets, eclipsing binary stars or asteroids – to observe,” she said.

“Each day consists of waking up around lunchtime, scheduling and preparing for the observing night, and then observing all through the night until sunrise, when we go to bed. It’s a really immersive experience; I did it last year and I’m delighted to be going back.”

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Dr Claire O’Connell is a scientist-turned-writer with a PhD in cell biology and a master’s in science communication