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Dr David Sobral, the astronomer who led a team to discover a galaxy that may contain the very first generation of stars, has joined Lancaster University as a lecturer. He will continue his research into searching for earlier and earlier galaxies. Dr Sobral has talked to SCAN about how he first became interested in Astrophysics and how his life’s work has led to him joining the University.
Born in the Portuguese town of Barreiro, Dr Sobral said that from a young age he was interested in the night sky. He told SCAN that he was “very lucky to spend a lot of time in the Alentejo region (south of Portugal), where you can get fantastic dark skies, and thus the Milky Way reveals itself in all its beauty. Of course I had no idea of what I was looking at when I was a kid, but it was still inspiring to look up, count “shooting stars” and wonder.”
Dr Sobral said that “ultimately that is the most beautiful ingredient to do Science: our endless, pure curiosity. I still find it equally, if not more, breath-taking. So having the chance to regularly look up at the sky in some of the best places in the World to do Astronomy has been truly spectacular.”
When he was slightly older, Sobral realised that he enjoyed Physics but also had an interest in a great deal of other subjects including Chemistry, Biology, Literature and coding.
A few months before starting university he was convinced that he was going to do literature because he loved to write fiction and poetry but ultimately he “figured out that Physics/Astrophysics was really what I wanted, as it would allow me to still pursue all my other interests and, most of all, to ask some of the most fundamental questions we can possibly ask about our origins, the Universe and everything.”
He said that “in practice, a few things really allowed me to figure that out: one was the book by João Magueijo, ‘Faster than the speed of light’, and the others were national competitions in which I participated and won, on topics of Physics and Astrophysics.”
In pursuit of these interests, Dr Sobral continued to write – both fiction as well as science-fiction. He also began to publish science outreach articles to newspapers both local and regional around Portugal.
Dr Sobral’s interest in Physics only grew as time went on and he said that he began reading more and more about the topic of Astronomy. He was particularly interested in “strange things (at the time, for me) like black holes, and understanding what they were, how they may form and the Physics behind them”. This led to him doing a “presentation about black holes for one national competition at the Lisbon’s Astronomical Observatory. That was a fantastic (although nerve-racking) experience which made a huge difference to whatever came next. At the same time, I was very interested in more theoretical Physics, including relativity.”
He went on to study for a BSc in Physics at the University of Lisbon, for which he’d felt like he’d make the right decision. “I was very lucky to have had great teachers in the first courses and, most of all, to have the opportunity to start doing research from the very first year of my BSc degree.”
After he completed that degree, Dr Sobral then moved on to the University of Edinburgh where he did his PhD in Astrophysics. His research at this time was about measuring and understanding the star formation history of the Universe. From observations taken at the United Kingdom Infrared Telescope (UKIRT) in Hawaii, Dr Sobral conducted a large survey of distant galaxies in order to measure how many stars the Universe was forming across its life. Results from this survey revealed that the production of stars across the Universe has been declining continuously over the last 11 billion years. At its peak of star production, the rate that new stars were being formed was 30 times faster.
Dr Sobral’s current research involves conducting very large surveys of the Universe across cosmic time to understand what is evolving throughout the Universe as well as trying to increase look-back times so that earlier galaxies can be observed. His main aim is to study the physics within distant galaxies and how they change across time. Also, he is studying and searching for how physical conditions in galaxies other than our own have shaped the formation and evolution of these galaxies.
On his transition to Lancaster University, Dr Sobral has said that “Lancaster’s new Observational Astrophysics group is a unique opportunity to really make a difference and to help to develop an excellent group within an already outstanding Physics Department. I really like the strategy and the way things work at Lancaster. I really did not feel comfortable with the complete lack of strategy, dynamics and ambition at the Lisbon University where I was before. Lancaster is so different in that respect, so I really feel at home.”