A large, international team of scientists has directly detected gravitational waves – ripples in space and time – from the spectacular collision of two neutron stars. It marks the first time that a cosmic event has been viewed in both gravitational waves and light.

The detection was made using the US-based Laser Interferometer Gravitational-Wave Observatory (LIGO); the Europe-based Virgo detector; and approximately 70 ground and space-based observatories.

Neutron stars are the smallest, densest stars known to exist and are formed when massive stars explode in supernovae. As these particular neutron stars spiralled together, they emitted gravitational waves that were detectable for about 100 seconds; when they collided, a flash of light in the form of gamma rays was emitted and seen on Earth about two seconds after the gravitational waves. In the days and weeks following the collision, other forms of light, or electromagnetic radiation — including X-ray, ultraviolet, optical, infrared, and radio waves — were detected.

Professor Mark Sullivan and Postdoctoral Fellow Dr Cosimo Inserra, of Physics and Astronomy, are part of the ePESSTO collaboration that led a Nature paper on the electromagnetic observation of this new neutron star event. It revealed a transient that has physical parameters that broadly match the theoretical predictions from neutron-star mergers (a ‘kilonova’), as well as the first direct evidence that such events are a major source for the synthesis of elements heavier then iron. Dr. Inserra comments, “The optical observations we made of this gravitational wave source revealed an astronomical event unlike any other previously observed. Our data show that events like this can be a major source for creating the very heaviest elements in the universe.â€?

Professor Ian Jones, Dr Wynn Ho and PhD student Emma Osborne from Mathematical Sciences at the University of Southampton, are part of the 1,200 strong LIGO team, made up of scientists from 16 different countries around the world. The LIGO-Virgo results are published today (16 October 2017) in the journal Physical Review Letters, with the ePESSTO observations of the electromagnetic counterpart published in Nature. Additional papers from the LIGO and Virgo collaborations and the astronomical community have been either submitted or accepted for publication in various journals.

In the weeks and months ahead, telescopes around the world will continue to observe the afterglow of the neutron star merger and gather further evidence about its various stages, its interaction with its surroundings, and the processes that produce the heaviest elements in the universe.

Astrophysicists from the University of Southampton have taken an important ‘first step’ toward increased collaboration with partners in Argentina.

Dr Diego Altamirano, a Principal Research Fellow from Southampton’s Department of Physics and Astronomy, is strengthening scientific relations with the National University of La Plata through a grant from The Royal Society’s International Exchanges scheme.

He hopes the project, titled ‘The first step for High-Energy Astrophysics relations between Argentina and the UK, will enhance the theoretical and observational expertise of both groups while opening new areas of research for the international partners.

“This new collaboration will help answer long-standing questions in high-energy astrophysics as we study a wide range of topics, from the physics of massive stars, to supernova remnants and accretion onto compact objects like black holes and neutron stars,â€? Diego explains.

“Having first studied in Argentina, I’m looking forward to sharing my 14 years of knowledge in the area of High-Energy Astrophysics and helping our new partners build a strong group that can complement our world-leading research in Southampton. I am confident that the projects proposed will be only the seed for a long-term collaboration and strengthening of both scientific groups in the UK and Argentina.â€?

Diego will work with scheme co-applicant Jorge Combi and colleagues at the National University of La Plata as they develop a proposal that involves PhD students, postdoctoral researchers and other staff members.

The collaboration will focus on two work packages, developing the analysis of X-ray data from state-of-the-art space observatories and complex, multi-wavelength modelling of the observational results. The combined results will help research partners assess how current facilities accessible to the different groups could be used to set up future novel observing programmes.

Find out more about Astronomy at Southampton through the Department’s research group website.

The University of Southampton has forged a new strategic partnership for public engagement with the Winchester Science Centre and Planetarium.

The partnership, launched at a special event held in Winchester, creates a new stage for world-leading research from the Department of Physics and Astronomy to reach the hearts and minds of visitors to the Science Centre.

Interactive displays at the popular site will soon include an exhibit on transistors, developed by an interdisciplinary University team including Professor David Smith, Head of Southampton’s Nanomaterials Group.

Professor Sir Christopher Snowden, President and Vice Chancellor of the University of Southampton, says: “It was my great pleasure to join with our colleagues from Winchester Science Centre and Planetarium to launch this new strategic partnership which represents a shared vision with the University of Southampton to use public engagement in science as a catalyst for activities that will lead us all to changing the world for the better.

“It’s vital for the University to access a number of platforms to publicly demonstrate the many features and benefits of our research and education. The Science Centre has been invaluable in working with us to achieve this goal over many years and I look forward to an even closer collaboration going forward as we explore ever more exciting ways to communicate our cutting-edge research and world-class education.â€?

The new transistors exhibit, which will be made available to the public in early 2018, will demonstrate the importance of transistors in modern electronics and present visitors with a physical analogue of a field effect transistor. The analogue will involve water representing electrical charge, with pressurised squeezing affecting flow through a long, thin balloon. The exhibit, which will be on display for a minimum of five years, combines expertise from Physics and Astronomy’s Professor David Smith, along with Professors Phil Bartlett and Gill Reid from the Department of Chemistry.

Ben Ward, CEO of Winchester Science Centre and Planetarium, adds: “Scientific public engagement has the potential to transform lives. It educates, empowers and inspires generations and encourages debate about topical issues that affect us all.

“Winchester Science Centre is thrilled to be working with cutting-edge researchers from the University of Southampton, helping to bridge the gap between academic research and the general public,â€? he added. “Our new partnership enables the Centre to highlight the importance of STEM learning through new interactive displays built in collaboration with the University, based on their world-changing research and how it impacts everyday life.â€?

Scientists from the University of Southampton and the Henan Institute of Science and Technology in Xinxiang, China, will search for companion states to the Higgs boson in new collaborative research scheme.

Professor Stefano Moretti from Southampton’s High Energy Physics Group will work alongside the Henan Institute’s Professor Yao-Bei Liu to explore 'New Physics beyond the Standard Model', drawing upon the latest data from the Large Hadron Collider (LHC).

The collaboration, which will start in September 2018, is being funded by the China Scholarship Council (CSC) and will involve an academic visit from the China to Southampton’s Department of Physics and Astronomy.

The research builds on the highly-publicised advances of the LHC at CERN and its discovery of the Higgs boson, an elementary particle in the Standard Model of particle physics.

“This collaboration is a natural continuation of my long-term endeavour of searching for new physics beyond the Standard Model, the current description of the particle physics world,â€? Stefano says. “We are at a crossroad in High Energy Particle Physics. A new and exciting era has begun with the arrival of data from the experiments on the LHC. The rapid and accurate interpretation of this data will point the way to a higher level of understanding of the fundamental interactions of matter and forces, as well as possibly paving the way towards an underlying grand unified theory. I’m delighted to have the support of the CSC as we continue this journey through the search for companion states to the Higgs boson.â€?

The CSC funding opens the door to a long term collaboration between the UK and China operating within the framework of the NExT Institute, a body directed by Stefano Moretti that brings together theorists and experimentalists in the process of new physics discovery. Professor Yao-Bei Liu will join the NExT Institute as a Visiting Professor next September for a one-year term.

Southampton’s High Energy Physics Group studies the most elementary constituents of matter, the basic forces of nature by which they interact, and their role in the early Universe. Find out more through the research group website.