The South African Astronomical Observatory and the Southern African Large Telescope are among the 70 ground- and space-based observatories that observed the explosion of two colliding neutron stars, immediately after their gravitational shock waves were detected by the U.S.-based Laser Interferometer Gravitational-Wave Observatory.
Neutron stars are the smallest, densest stars known. They are the remains of massive stars which exploded as supernovae. In this particular event, dubbed GW170817, two such neutron stars spiralled inwards and then collided, emitting gravitational waves that were detectable for about 100 seconds. The collision also resulted in a kilonova explosion of light, initially in the form of gamma rays which were detected by space-based telescopes. The gamma rays were then followed by X-rays, ultraviolet, optical, infrared, and radio waves.
This allowed astronomers to localise the event within hours and launch follow-up observations by SALT and numerous other telescopes in South Africa and around the world. South African activities also included the first observations contributing to published scientific results by the MeerKAT radio telescope under construction in the Karoo.
Gravitational waves from colliding black holes were first detected only two years ago, and have been detected three more times since then, leading to the 2017 Nobel Prize in Physics being awarded to three US scientists. Black hole collisions, however, are not expected to emit light. GW170817 is the first time light and gravitational waves from the same event have been observed.
The significance of the present event lies in the combination of the gravitational waves and light. “Imagine you have only one sense”, explains Petri Vaisanen, Head of SALT Astronomy Operations, who was the observer at SALT during the frantic search for the counterpart for the gravitational wave event. “All your life you have merely looked at the world. Two years ago you heard something, voices coming from somewhere around you. But then, suddenly, you actually see someone talking. How much more will you understand about how the world works when you put those together? Immensely more. That to me sums up the momentous discovery, and hints at the possibilities going forward.”
August 18, 2017, the day and night following the LIGO detection and the initial successful searches in Chile for the counterpart, was a busy day for observational astronomers. “After a flurry of messages and emails that afternoon in Sutherland, I finally got the coordinates”, continues Vaisanen. “There was a new object, which had caused the whole of space-time to ripple, sitting at the outskirts of the galaxy NGC 4993 some 130 million light-years away. I knew that everyone with a working telescope in the Southern Hemisphere was scrambling to get data on it. We decided to drop all other plans for that evening, and went for a spectral observation with SALT, since you need a large telescope for such observations breaking up the light into all its colours. It was a difficult observation since we had to do it in twilight, before it got properly dark. I’m very proud of the whole team, SALT was only the third observatory to provide a spectrum of the target, and the first spectrum that clearly started showing anomalous behaviour proving that this was no run-of-the-mill transient event”.
The significance of getting early observations stems from the afterglow of the collision changing very rapidly. Piecing together the new science from the event requires combining observations spanning the first hours, days and weeks after the merger. The first SALT spectrum has a very prestigious spot in the combined scientific paper, with thousands of authors and hundreds of institutions. In addition, several, more detailed scientific papers have also been written based on SALT, SAAO and other Sutherland observations.
“Finally, the irony of the moment for me, anxiously sitting at the telescope that evening looking at the new object, was that just three weeks before I had attended a meeting discussing the future of optical searches of gravitational waves and the SAAO part in it. There were arguments that it could be decades before we are able to localise such events well enough for observations, and it would probably not be worth expending the effort. It’s amazing how quickly things change.”
Sutherland telescopes reveal the details of the neutron star merger
Theorists have predicted that what follows the initial collision is a “kilonova” explosion— a phenomenon by which the material that is left over from the neutron star collision, which glows with light, is blown out of the immediate region, far out into space. The light-based observations from other large international telescopes show that heavy elements, such as lead and gold, are created in these collisions and subsequently distributed throughout the universe – confirming the theory that a major source for the creation of elements heavier than iron does, indeed, results from these neutron star mergers.
The early SALT observations showed that the explosion was relatively bright and blue. Only two or three days later, further observations by SALT, SAAO and other major international telescopes showed that the light was rapidly fading and turning red, due to the dusty debris blocking the bluer light, as predicted by the theory of the evolution of a kilonova explosion. Simultaneously, MASTER (a joint Russian-South African optical telescope located in Sutherland) and IRSF (Infra-Red Survey Facility; a joint Japanese-South African infrared telescope also in Sutherland) continued to monitor GW170817 for two weeks, showing that it gradually faded in the visible light but brightened in the infrared, consistent with the final stages of the afterglow from the surrounding debris.
The results of this unprecedented event have demonstrated the importance of collaborative multi-messenger observations and mark a new era in astronomy. “The ability of SALT and SAAO telescopes to respond rapidly to unexpected discoveries is a major reason for the success of these observations and will ensure similar successes in the future”, says Dr Stephen Potter, Head of Astronomy at the SAAO. “We are very proud to have played a major role in such a historical event thanks to the sterling efforts and expertise of SAAO and SALT staff who ensure that our observatory is at the forefront of world-class scientific endeavours.”
Legion gets a pro makeover
Lenovo’s latest Legion gaming laptop, the Y530, pulls out all the stops to deliver a sleek looking computer at a lower price point, writes BRYAN TURNER
Gaming laptops have become synonymous with thick bodies, loud fans, and rainbow lights. Lenovo’s latest gaming laptop is here to change that.
The unit we reviewed housed an Intel Core i7-8750H, with an Nvidia GeForce GTX 1060 GPU. It featured dual storage, one bay fitted with a Samsung 256GB NVMe SSD and the other with a 1TB HDD.
The latest addition to the Legion lineup has become far more professional-looking, compared to the previous generation Y520. This trend is becoming more prevalent in the gaming laptop market and appeals to those who want to use a single device for work and play. Instead of sporting flashy colours, Lenovo has opted for an all-black computer body and a monochromatic, white light scheme.
The laptop features an all-metal body with sharp edges and comes in at just under 24mm thick. Lenovo opted to make the Y530’s screen lid a little shorter than the bottom half of the laptop, which allowed for more goodies to be packed in the unit while still keeping it thin. The lid of the laptop features Legion branding that’s subtly engraved in the metal and aligned to the side. It also features a white light in the O of Legion that glows when the computer is in use.
The extra bit of the laptop body facilitates better cooling. Lenovo has upgraded its Legion fan system from the previous generation. For passive cooling, a type of cooling that relies on the body’s build instead of the fans, it handles regular office use without starting up the fans. A gaming laptop with good passive cooling is rare to find and Lenovo has shown that it can be achieved with a good build.
The internal fans start when gaming, as one would expect. They are about as loud as other gaming laptops, but this won’t be a problem for gamers who use headsets.
Click here to read about the screen quality, and how it performs in-game.
Serious about security? Time to talk ISO 20000
By EDWARD CARBUTT, executive director at Marval Africa
The looming Protection of Personal Information (PoPI) Act in South Africa and the introduction of the General Data Protection Regulation (GDPR) in the European Union (EU) have brought information security to the fore for many organisations. This in addition to the ISO 27001 standard that needs to be adhered to in order to assist the protection of information has caused organisations to scramble and ensure their information security measures are in line with regulatory requirements.
However, few businesses know or realise that if they are already ISO 20000 certified and follow Information Technology Infrastructure Library’s (ITIL) best practices they are effectively positioning themselves with other regulatory standards such as ISO 27001. In doing so, organisations are able to decrease the effort and time taken to adhere to the policies of this security standard.
ISO 20000, ITSM and ITIL – Where does ISO 27001 fit in?
ISO 20000 is the international standard for IT service management (ITSM) and reflects a business’s ability to adhere to best practice guidelines contained within the ITIL frameworks.
ISO 20000 is process-based, it tackles many of the same topics as ISO 27001, such as incident management, problem management, change control and risk management. It’s therefore clear that if security forms part of ITSM’s outcomes, it should already be taken care of… So, why aren’t more businesses looking towards ISO 20000 to assist them in becoming ISO 27001 compliant?
The link to information security compliance
Information security management is a process that runs across the ITIL service life cycle interacting with all other processes in the framework. It is one of the key aspects of the ‘warranty of the service’, managed within the Service Level Agreement (SLA). The focus is ensuring that the quality of services produces the desired business value.
So, how are these standards different?
Even though ISO 20000 and ISO 27001 have many similarities and elements in common, there are still many differences. Organisations should take cognisance that ISO 20000 considers risk as one of the building elements of ITSM, but the standard is still service-based. Conversely, ISO 27001 is completely risk management-based and has risk management at its foundation whereas ISO 20000 encompasses much more
Why ISO 20000?
Organisations should ask themselves how they will derive value from ISO 20000. In Short, the ISO 20000 certification gives ITIL ‘teeth’. ITIL is not prescriptive, it is difficult to maintain momentum without adequate governance controls, however – ISO 20000 is. ITIL does not insist on continual service improvement – ISO 20000 does. In addition, ITIL does not insist on evidence to prove quality and progress – ISO 20000 does. ITIL is not being demanded by business – governance controls, auditability & agility are. This certification verifies an organisation’s ability to deliver ITSM within ITIL standards.
Ensuring ISO 20000 compliance provides peace of mind and shortens the journey to achieving other certifications, such as ISO 27001 compliance.