LILLI SUN

Former OzGrav PhD student Lilli Sun has returned to the welcoming arms (virtual—social distancing, right!) of OzGrav as our new Associate Investigator. Lilli tells us about her career journey over the last seven years…
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Seven years ago, I was a project manager in IBM China System and Technology Lab, leading software development for IBM Storage products. I started working in that group as a software engineer right after getting my Master’s degree in Engineering in Shanghai Jiao Tong University. I liked the job, but couldn’t stop thinking about the things I loved better: physics, general relativity, black holes, etc… That year, I wrote an email to Prof. Andrew Melatos at the University of Melbourne (UoM), asking about the possibility of doing a PhD program on gravitational waves, which completely changed the direction of my life.

Six years ago, I started my PhD candidature in Andrew’s group, mainly working on continuous-wave data analyses. Lacking background knowledge, I spent a lot effort catching up on maths and physics. It was great fun going back to classes, doing homework, and sitting in exams. Meanwhile, I started working on a novel method introduced and developed by the UoM group — the Viterbi tracking. I remembered calculating the Viterbi paths in exams when I was an undergrad in Engineering school. That felt like, déjà vu.

Five years ago, GW150914 happened, followed by all kinds of excitement including a golden multi-messenger event. I could not conceive of a more exciting PhD life! In those years, I implemented the first Viterbi search pipeline; analysed the first set of Advanced LIGO data, targeting Sco X-1; and then, extended my work to many other types of fascinating sources: young neutron stars, remnants of binary neutron star mergers, and ultralight bosons.

Two years ago, I left Australia and started a postdoc position in the LIGO Lab at Caltech, after getting my degree.  I continued looking for waves from neutron stars and conjectured boson clouds, and I spent a lot time at the two LIGO sites, calibrating the detectors. Getting to know the complicated instruments made me feel much better than treating the data purely as output of a giant black box. I miss the time in the desert and swamp, which was quiet, special, and accompanied by many friends.
This has been a difficult year for everyone, starting with bush fires throughout Australia, followed by COVID-19. Setting all of those aside, I couldn’t feel more excited to come back to Australia as a research fellow at the Australian National University and as an OzGrav Associate Investigator, starting a new journey in gravitational astrophysics research. A few years after I got into this field, detecting transient events has become a daily routine. I cannot wait to see what lies ahead. But first of all, I hope the global pandemic will come to an end soon, and that we can meet each other in person again!