Dr Joseph Lyman, UKRI Future Leaders Fellowship
New Frontiers in Transient Astrophysics: Gravitational-Wave Multi-Messenger Events and Exotic Stellar Explosions
How and where did the elements of the universe form? How do stars live and die? What is the ultimate fate of the Universe? As part of Warwick's Astronomy and Astrophysics Group, Dr Joseph Lyman will use his Fellowship to further our understanding of the most extreme events and questions posed by the universe.
When massive stars, more than eight times the mass of our sun, reach the end of their lives, they collapse due to their own gravity and produce a neutron star or black hole.
During this rapid and catastrophic collapse, large amounts of chemically-enriched material are expelled into the universe in an extremely luminous event called a supernova.
These chemically-enriched innards are essential for life as we know it, containing carbon, oxygen and iron.
What's more, these elements form the next generation of stars and planets, seeding the building blocks of life.
The Warwick-led Gravitational Wave Optical Transient Observer (GOTO) will continuously monitor the night-sky for new supernovae (Copyright Krzysztof Ulaczyk).
Monitoring the night-sky for new supernovae
To fully understand supernovae, and the stars that give rise to them, observations from networks of telescopes must be made rapidly upon explosion. Since we don't know where or when a supernova will occur, this Fellowship will exploit the Warwick-led Gravitational Wave Optical Transient Observer (GOTO - pictured above right), which will continuously monitor the night-sky for new supernovae.
Dr Lyman's work will create a world-leading rapid observatory network by connecting supernova discoveries by GOTO with larger telescopes nearby to routinely perform detailed observations within hours of a supernova's discovery. This will provide insight into the nature of the exploding stars (such as their size and mass) and the energetics and chemical makeup of the explosions. This knowledge is essential to build a complete picture of how stars die, and how the chemical fingerprint of our universe was formed.
Two neutron stars collide around 130 million light years away (Copyright University of Warwick/Mark Garlick).
Ripples in space-time and merging black holes
After massive stars die as supernovae, their journey isn't quite over. Recent breakthroughs mean we can now detect them 'beyond the grave' as their neutron star and black hole corpses violently merge.
The Fellowship will build on Dr Lyman's early work in the field of gravitational-wave multi-messenger astrophysics. In 2015, a completely new signal from the universe was detected: Minute ripples in space-time. The ripples were caused by two black holes merging 1.3 billion light years away and are known as gravitational-waves. Their detection confirms a century-old prediction by Einstein.
As well as seeing, with the detection of gravitational-waves, we can now 'hear' the universe. Just as our senses combine to give us far more information than they do alone, so too does combining light we see and gravitational-waves we hear from astrophysical events.
When neutron stars collide
This 'multi-messenger' era of gravitational-wave research began in 2017 with the first ever event discovered in both light (photons) and gravitational-waves.
The event, named GW170817, was the result of two neutron stars colliding around 130 million light years away and became one of the most intensely studied objects in the universe. We still have only observed a single event of this kind. To enhance our knowledge, we must observe similar events to understand their diversity and how often they occur in the universe.
Dr Lyman's project will develop the GOTO observatory and collaborate with international teams to find and study the next gravitational-wave multi-messenger events, placing the fellowship at the forefront of the international effort to realise the potential of this exciting new window on the Universe.