Earlier this year, GRADnet launched its Entrepreneurship in Action Challenge tailored for Physics PGRs in SEPnet to get involved.

As part of the Challenge, SEPnet institutions were invited to form teams of PGR researchers to compete to be the most entrepreneurial physics department in SEPnet. Teams were formed from Kent, Portsmouth, QMUL, Southampton, Surrey, and Sussex.

During the six month project the teams have undertaken an exciting, and sometimes gruelling, journey to develop their ideas into marketable proposals. The teams from across the network gathered on 13 July to present their business ideas to a panel industry judges. Neil Phillipson of Outsideology, Simon Bland of Reigate and Banstead Borough Council and Phil Edwards of Weald Technology were all impressed by the quality, credibility and potential of the ideas being showcased. They commented that it was impressive to see physics PhD students applying their skills to challenges and scenarios outside of their normal environment. They agreed that the creative thinking and entrepreneurial mindset demonstrated by the teams would be an asset to any industry or organisation.

The winning team from the University of Southampton comprised of Azaria Coupe, Anthony Preston, Andrew Lawson, and Marc Scott.

The achievements of all the teams were celebrated at the follow-on networking event which brought together the students and local entrepreneurial businesses.

Dr Diego Altamirano from the University of Southampton has contributed to new research that has proved the existence of a ‘gravitational vortex’ around a black hole.

The discovery, published in the journal Monthly Notices of the Royal Astronomical Society, solves a mystery that has eluded astronomers for more than 30 years and will allow them to map the behaviour of matter very close to black holes. It could also open the door to future investigations of Albert Einstein's theory of general relativity.

Matter falling into a black hole heats up and radiates back into space as X-rays. In the 1980s, astronomers discovered that the X-rays coming from black holes flicker, a phenomenon called Quasi Periodic Oscillation (QPO). QPOs are associated with a gravitational effect predicted by Einstein's general relativity: that a spinning object will create a kind of gravitational vortex.

“It is a bit like twisting a spoon in honey. Imagine that the honey is space and anything embedded in the honey will be 'dragged' around by the twisting spoon,â€? explains lead author Adam Ingram from the University of Amsterdam, who began working to understand QPOs for his PhD in 2009. “In reality, this means that anything orbiting a spinning object will have its motion affected.â€?

Together with colleagues, Ingram published a paper in 2009 suggesting that the QPO is driven by this Lense-Thirring effect, when the flat disc of matter surrounding a black hole, known as an ‘accretion disc’ spirals inwards towards the black hole. Close to the black hole, the accretion disc puffs up into a hot plasma, termed the hot inner flow, which shrinks as it is eaten by the black hole.

The inner flow releases high energy radiation that strikes the matter in the surrounding accretion disc, making the iron atoms in the disc shine like a fluorescent light tube. Instead of visible light, the iron releases X-rays of almost a single wavelength - referred to as ‘a line’. Because the accretion disc is rotating, the line will sometimes shine on the approaching disc material and sometimes on the receding material, making the line wobble back and forth.

Using ESA’s orbiting X-ray observatory, XMM-Newton, along with NASA's NuSTAR X-ray observatory, Dr Altamirano and colleagues from Amsterdam, Cambridge, Durham and Tokyo watched the QPO of black hole H 1743-322.

Dr Altamirano, Royal Society University Research Fellow at the University of Southampton, said: “After adding all the observational data together, we saw that the iron line was wobbling in accordance with the predictions of general relativity. This meant we were directly measuring the motion of matter in a strong gravitational field near to a black hole – the first time that the Lense-Thirring effect has been measured in a strong gravitational field.â€?

The technique will allow astronomers to map matter in the inner regions of accretion discs around black holes. It also hints at a powerful new tool with which to test general relativity.

Einstein's theory is largely untested in such strong gravitational fields. So if astronomers can understand the physics of the matter that is flowing into the black hole, they can use it to test the predictions of general relativity as never before - but only if the movement of the matter in the accretion disc can be completely understood.

“This is a major breakthrough since the study combines information about the timing and energy of X-ray photons to settle the 30-year debate around the origin of QPOs. The photon collecting capability of XMM-Newton was instrumental in this work,â€? says Norbert Schartel, ESA Project Scientist for XMM-Newton.

A Talk by Professor Laurent Lellouch of the National Center for Scientific Research, (CNRS) and Aix-Marseille University, France.

The origin of mass is mysterious. In our everyday experience, the mass of an object is the sum of the mass of its parts. However, in the world of subatomic particles such as quarks and gluons, this everyday assumption is no longer true and even very small mass differences can have cosmic consequences. After an introduction to the subatomic world and the mechanisms by which mass emerges, I will describe how supercomputers are being used to compute from first principles the interactions between elementary particles in order to reveal the origins of mass and to explain the stability of the matter which constitutes us and the visible universe.

Monday 25 July, 19:00 - 20:00 Lecture Theatre 1067, Building 58, University of Southampton Highfield, Southampton, SO17 1BJ

Sign up and book your place today

Measurements of unprecedented detail returned by Japan’s Hitomi X-ray satellite have discovered that the gas in the Perseus cluster of galaxies is much less turbulent than expected.

Most of the gas in the Universe lies between galaxies so understanding how turbulence mixes this gas allows astronomers to explore how galaxies form and evolve.

Hitomi suffered a fatal anomaly in March, one month after launch. But before its untimely demise, Hitomi was able to peer into the Perseus cluster of galaxies, a collection of thousands of galaxies bound together by gravity. Located about 240 million light-years away, the Perseus galaxy cluster contains a vast amount of extremely hot gas. At temperatures averaging 90 million degrees Fahrenheit (50 million degrees Celsius), the gas glows brightly in X-rays.

Prior to Hitomi’s launch, astronomers lacked the capability to measure the detailed dynamics of this gas, particularly its relationship to bubbles of gas expelled by an active supermassive black hole in the cluster’s core galaxy, NGC 1275.

Earlier studies explored the pressure of gas between Perseus’s galaxies. Hitomi looked instead at turbulence within the gas, because those motions can affect measurements of a cluster's mass and estimates of how galaxies come together.

Researchers discovered that superheated gas at the cluster’s heart flows much more calmly than expected, given the amount of astrophysical action in the region. Hitomi’s X-ray spectrometer revealed gas moving at 164 kilometres per second (365,000 miles an hour) – enormous by human standards but surprisingly modest on cosmic scales. The results, published in the journal Nature, indicate that turbulence is responsible for just four per cent of the energy stored in the gas as heat.

Dr Poshak Gandhi, Associate Professor and STFC Ernest Rutherford Fellow in the University of Southampton’s Astronomy Group, was one of over 200 astronomers from over 60 contributing institutions in Japan, the US, Canada and Europe involved in the major international collaboration.

He said: “Hitomi has revealed the tremendous scientific potential of next generation X-ray astronomy. This is only the first peek into a universe of discoveries. For instance, Hitomi was supposed to observe all kinds of growing black holes in order to learn how these ultra-dense objects grow and evolve. Unfortunately, we could not gather data on any isolated black holes before Hitomi's anomaly. Many questions will remain unanswered for now.â€?

“Of course we had a programme planned to look at more clusters, and we would have carried on for the next few years had it only lived,â€? says Andrew Fabian, an astronomer at the University of Cambridge and a member of the Hitomi team. “It feels like the door has been briefly opened, showing us a new and exciting landscape — and it’s been slammed in our face again.â€?

Led by the Japan Aerospace Exploration Agency (JAXA), Hitomi launched on 17 February and made the Perseus observations on 25 February and 4 March, weeks before suffering a mission-ending spacecraft anomaly on 26 March.

Hitomi’s revolutionary Soft X-ray Spectrometer (SXS) provided 30 times the detail of the best previous observation. Hitomi’s SXS could measure the turbulence in the cluster to a precision of 10 kilometres/second, whereas previous observations could only constrain the speed to be lower than 500 kilometres/second.

The new Hitomi measurements aren’t quite as precise as they could have been, because the team had not gone through all its calibrations before losing the satellite. The data were gathered through one of the main shutters still partly shut and blocked by a protective valve, which underlines the true potential that Hitomi could have demonstrated once fully operational. However, the Perseus work is likely to stand as Hitomi’s primary scientific legacy.

Dr Gandhi said: “It is time to turn our attention to the future. Toward this end, in February of next year, we will be organising a UK-wide meeting at the Royal Astronomical Society in London to discuss future strategies for X-ray astronomy. We hope to build upon the momentum that Hitomi has provided. The UK has been a pioneer in this field for many years, and it can play an enhanced leadership role if there is the community-wide will to do so.â€?

The next mission that will be capable of fully following up the Hitomi programme is the European Space Agency’s ATHENA , an X-ray observatory scheduled for launch in 2028. ATHENA will have 100 times more collecting area and 100 times more pixels than Hitomi. Among the key scientific objectives of ATHENA are to investigate the evolution of clusters of galaxies including their interplay with energy injection from supermassive black holes.

The supermassive black holes found at the centre of every galaxy, including our own Milky Way, may, on average, be smaller than we thought, according to work led by astronomer Dr Francesco Shankar.

If he and his colleagues are right, then the gravitational waves produced when they merge will be harder to detect than previously assumed. The international team of scientists published their results in Monthly Notices of the Royal Astronomical Society.

Supermassive black holes have been found lurking in the cores of all galaxies observed with high enough sensitivity. Despite this, little is known about how they formed. What is known is that the mass of a supermassive black hole at the centre of a galaxy is related to the total mass and the typical speeds (the "velocity dispersion") of the stars in its host.

The very existence of this relationship suggests a close co-evolution between black holes and their host galaxies, and understanding their origin is vital for a proper model of how galaxies and black holes form and evolve. This is because many galaxy evolution models invoke powerful winds and/or jets from the central supermassive black hole to control or even stop star formation in the host galaxy (so-called "quasar feedback"). Alternatively, multiple mergers of galaxies - and their central black holes - are also often suggested as the primary drivers behind the evolution of massive galaxies.

Despite major theoretical and observational efforts in the last decades, it remains unclear whether quasar feedback actually ever occurred in galaxies, and to what extent mergers have truly shaped galaxies and their black holes.

The new work shows that selection effects – where what is observed is not representative – have significantly biased the view of the local black hole population. This bias has led to significantly overestimated black hole masses. It suggests that modellers should look to velocity dispersion rather than stellar mass as the key to unlocking the decades-old puzzles of both quasar feedback and the history of galaxies.

With less mass than previously thought, supermassive black holes have on average weaker gravitational fields. Despite this, they were still able to power quasars, making them bright enough to be observed over distances of billions of light years.

Unfortunately, it also implies a substantial reduction in the expected gravitational wave signal detectable from pulsar timing array experiments. Ripples in spacetime that were first predicted by Albert Einstein in his general theory of relativity in 1915; gravitational waves were finally detected last year and announced by the LIGO team this February. The hope is that coming observatories can observe many more gravitational wave events, and that it will provide astronomers with a new technique for observing the universe.

Dr Shankar comments: “Gravitational wave astronomy is opening up an entirely new way of observing the universe. Our results though illustrate how challenging a complete census of the gravitational background could be, with the signals from the largest black holes being paradoxically among the most difficult to detect with present technology.â€?

Researchers expect pairs of supermassive black holes, found in merging galaxies, to be the strongest sources of gravitational waves in the universe. However, the more massive the pairs, the lower the frequencies of the emitted waves, which become inaccessible to ground based interferometers like LIGO. Gravitational waves from supermassive black holes can however be detected from space via dedicated gravitational telescopes (such as the present and future ESA missions LISA pathfinder and eLISA), or by a different method using ‘pulsar timing arrays’.

These devices monitor the collapsed, rapidly rotating remnants of massive stars, which have pulsating signals. Even this method though is still a few years from making a detection, according to a follow-up study by the same team expected to appear in another Monthly Notices paper later this year.