Interview with Lucy Oswald
Lucy Oswald joined the Cavendish in January as our new Assistant Professor in Data-Driven Radio Astronomy. Her research focuses on pulsars, the enigmatic neutron stars famously discovered in Cambridge by Dame Jocelyn Bell Burnell. Lucy is building on that legacy and forging a path for future generations.
Can you tell us who you are and what you work on?
I’m an Assistant Professor in Data-Driven Radio Astronomy at the University of Cambridge. And the clue to what I work on is in the two parts of that title: the data-driven side and the radio astronomy side. I study pulsars, which are neutron stars that emit beams of radio waves. They were discovered over half a century ago, and we still don’t really understand how or why they produce those beams.
Part of my work is about studying that emission directly, by observing as many pulsars as possible and looking for trends in their behaviour. The other part is using pulsars as tools, because their radio waves travel through the Milky Way and interact with things like dust, plasma and magnetic fields. That lets us build up maps of parts of the galaxy that we otherwise wouldn’t be able to see. It’s a lot of detective work, and it’s a lot of fun.
What first drew you to astrophysics, and why pulsars specifically?
I think it was a combination of things. One was just the excitement of astrophysics: the big open questions, trying to understand space and the extremes of what’s possible. The other was that as I studied physics, I realised that what I really enjoyed was the computational side: playing with data, extracting trends, looking at statistics.
Those two things came together quite naturally in astrophysics. I did some undergraduate projects on galaxies, but I actually came to pulsars almost by chance, during a PhD interview. We ended up discussing a pulsar paper, and I found the conversation so interesting that I ended up asking if my interviewer was offering a PhD project.
The pulsar research field is so dynamic and there is such a wide range of things you can investigate with them – there will be a connection to just about every area of physics you can think of! I barely knew about pulsars during my undergraduate degree, but once that opportunity appeared, I thought, right, this is the thing for me, and I’ve never regretted it.
“She’s been a fantastic source of advice, perspective and common sense. She’s an extraordinary role model.”
Lucy Oswald on Professor Dame Jocelyn Bell Burnell
What does ‘big data’ look like in pulsar astronomy?
I feel quite privileged actually, because I’ve seen this growth happen in real time. In my first PhD project I studied one pulsar. Then it became two, then eightyfour, then around three hundred. Now I’m part of a project called the Thousand Pulsar Array, where we monitor hundreds of pulsars every single month.
The data are big in lots of different ways. We’re looking at many pulsars, we’re observing them repeatedly over time, and within each observation you have huge numbers of individual pulses. Each pulse can look different, and then on top of that you’re observing across many radio frequencies.
So it’s not just the quantity of data, it’s also the number of dimensions of that data set, which means that there are many different avenues to explore.
What’s the research question you’re most obsessed with right now?
The big questions I’m currently trying to answer are: Why is pulsar radio emission time-variable, and how does the pulsar magnetic field evolve over its lifetime? I’m particularly interested in using the polarisation of pulsar radio emission to answer these questions, because it gives you direct information about the magnetic fields around the neutron star, which makes it an exciting diagnostic tool.
Advancing our understanding of pulsar physics enables us to push the boundaries of the laws of physics at the extremes – densities, magnetic fields, temperatures – and it also affects how well we can use pulsars as tools, for things like studying the Galaxy or even searching for gravitational waves.
How would you describe the current landscape for women in astrophysics?
There’s still a gender imbalance, although astrophysics is generally more balanced than some other areas of physics. I’ve always found it a welcoming and friendly environment, and I’ve never really felt that being a woman was an issue daytoday personally. But I try not to comment on generalities based on my own personal experiences – it’s much more instructive to consider large-scale trends and notice which people are absent from the community.
The biggest change for me recently has been having a child and taking maternity leave. Research timelines don’t stop, and that can be challenging. I was fortunate to have lots of support and flexibility, but I never fully left work, even though I was officially on maternity leave. I’m very aware that this can have wider systemic effects, particularly for early career researchers, and that this is going to predominantly impact women. This is not specific to astrophysics or even physics, it’s a wider research issue.
Have mentors or role models made a decisive difference for you?
Absolutely. My PhD supervisor, Aris Karastergiou, and a close collaborator, Simon Johnston, were incredibly supportive. Early on, they made it clear that no question was a silly question, which gave me the confidence to explore ideas properly.
I’d also mention Professor Dame Jocelyn Bell Burnell. I was very lucky to get to know her during my PhD, and she’s been a fantastic source of advice, perspective and common sense. She’s an extraordinary role model.
“It’s a lot of detective work, and it’s a lot of fun.”
To conclude, what would you say to a girl who loves space but doesn’t feel she belongs in physics?
Physics, and especially astrophysics, is often seen as very technical or very mathematical, and of course maths is part of it. But at its heart, it’s incredibly creative. You’re thinking about possibilities, asking what if, coming up with ideas about how the universe might work.
If you’re excited and curious, that’s what matters. You don’t have to fit a stereotype. Most people in the field are there simply because they’re fascinated by the questions.