In the latest discovery, the H.E.S.S. (a telescope that is operated by an international collaboration of scientists) has found three extremely luminous gamma-ray sources in the Large Magellanic Cloud (LMC), a satellite dwarf galaxy of the Milky Way.
These are objects of different types, namely the most powerful pulsar wind nebula; the most powerful supernova remnant; and a shell of 270 light years in diameter blown by multiple stars, and supernovae – a so-called superbubble.
The discovery is announced in the latest edition of the scientific journal, Science, in a research paper titled: The exceptionally powerful TeV ƴ-ray emitters in the Large Magellanic Cloud, which was published on Friday, 23 January 2015.
“This is a very important breakthrough for the team,” says Professor Sergio Colafrancesco, DST/NRF SKA Research Chair in the Wits School of Physics. “It paves the way to study external galaxies with very high-E telescopes such as H.E.S.S and then later with the planned Cherenkov Telescope Array (CTA) in Namibia. It will lead us to re-examine galaxy evolution and answer questions such as how high-E particles can affect the evolution of cosmic structures in the universe, principally galaxies, and the life cycles of matter in galaxies,” he adds.
Very high-energy gamma rays are the best tracers of cosmic accelerators such as supernova remnants and pulsar wind nebulae – end-products of massive stars. There, charged particles are accelerated to extreme velocities. When these particles encounter light or gas in and around the cosmic accelerators, they emit gamma rays. Very high-energy gamma rays can be measured on Earth by observing the Cherenkov light emitted from the particle showers produced by incident gamma rays high up in the atmosphere using large telescopes with fast cameras.
The Large Magellanic Cloud (LMC) is a dwarf satellite galaxy of our Milky Way, located about 170.000 light years away and showing us its face. New, massive stars are formed at a high rate in the LMC, and it harbors numerous massive stellar clusters. The LMC’s supernova rate relative to its stellar mass is five times that of our Galaxy. The youngest supernova remnant in the local group of galaxies, SN 1987A, is also a member of the LMC. Therefore, the H.E.S.S. scientists dedicated significant observation to searching for very high-energy gamma rays from this cosmic object.
For a total of 210 hours, H.E.S.S. has observed the largest star-forming region within the LMC called Tarantula Nebula. For the first time in a galaxy outside the Milky Way, individual sources of very high-energy gamma rays could be resolved: three extremely energetic objects of different types.
The so-called superbubble 30 Dor C is the largest known X-ray-emitting shell and appears to have been created by several supernovae and strong stellar winds. Superbubbles are broadly discussed as (complementary or alternative to individual supernova remnants) factories where the galactic cosmic rays are produced. The H.E.S.S. results demonstrate that the bubble is a source of, and filled by, highly energetic particles. The superbubble represents a new class of sources in the very high-energy regime.
Pulsars are highly magnetized, fast rotating neutron stars that emit a wind of ultra-relativistic particles forming a nebula. The most famous one is the Crab Nebula, one of the brightest sources in the high-energy gamma-ray sky. The pulsar PSR J0537−6910 driving the wind nebula N 157B discovered by the H.E.S.S. telescopes in the LMC is in many respects a twin of the very powerful Crab pulsar in our own Galaxy. However, its pulsar wind nebula N 157B outshines the Crab Nebula by an order of magnitude, in very high-energy gamma rays. Reasons are the lower magnetic field in N 157B and the intense starlight from neighboring star-forming regions, which both promote the generation of high-energy gamma rays.
The supernova remnant N 132D, known as a bright object in the radio and infrared bands, appears to be one of the oldest – and strongest – supernova remnants still glowing in very high-energy gamma rays. Between 2500 and 6000 years old – an age where models predict that the supernova explosion front has slowed down and it ought no longer to be efficiently accelerating particles – it still outshines the strongest supernova remnants in our Galaxy. The observations confirm suspicions raised by other H.E.S.S. observations, that supernova remnants can be much more luminous than thought before.
Observed at the limits of detectability, and partially overlapping with each other, these new sources challenged the H.E.S.S. scientists. The discoveries were only possible due to the development of advanced methods of interpreting the Cherenkov images captured by the telescopes, improving in particular the precision with which gamma-ray directions can be determined.
Indeed, the new H.E.S.S. II 28 m telescope will boost the performance of the H.E.S.S. telescope system, and in the more distant future the planned Cherenkov Telescope Array (CTA) will provide even deeper and higher-resolution gamma-ray images of the LMC – in the plans for science with CTA, the satellite galaxy is already identified as a “Key Science Project” deserving special attention.
· The H.E.S.S. telescope is operated by an international collaboration of scientists with a strong involvement by South African universities, in particular Wits University, North West University, and the Universities of the Free State and Johannesburg. Wits physicists are particularly involved in data analysis techniques, the development of theoretical interpretation tools of both extragalactic and galactic sources, and in the operational shifts at the telescope location in Namibia.
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Meet Aston Martin F1’s incredible moving data centre
The Aston Martin Red Bull Racing team faces a great deal more IT challenges than your average enterprise as not many IT teams have to rebuild their data center 21 times each year and get it running it up in a matter of hours. Not many data centers are packed up and transported around the world by air and sea along with 45 tonnes of equipment. Not many IT technicians also have to perform a dual role as pit stop mechanic.
The trackside garage at an F1 race is a tight working environment and a team of only two IT technicians face pressure from both the factory and trackside staff to get the trackside IT up and running very fast. Yet, despite all these pressures, Aston Martin Red Bull Racing do not have a cloud-led strategy. Instead they have chosen to keep all IT in house.
The reason for this is performance. F1 is arguably the ultimate performance sport. A walk round the team’s factory in Milton Keynes, England, makes it abundantly clear that the whole organization is hell bent on maximizing performance. 700 staff at the factory are all essentially dedicated to the creation of just two cars. The level of detail that is demanded in reaching peak performance is truly mind blowing. For example, one machine with a robotic arm that checks the dimensions of the components built at the factory is able to measure accuracy to a scale 10 times thinner than a human hair.
This quest for maximum performance, however, is hampered at every turn by the stringent rules from the F1 governing body – the FIA. Teams face restrictions on testing and technology usage in order to prevent the sport becoming an arms race. So, for example, pre-season track testing is limited to only 8 days. Furthermore, wind tunnel testing is only allowed with 60% scale models and wind tunnel-usage is balanced with the use of Computational Fluid Dynamics (CFD) software, essentially a virtual wind tunnel. Teams that overuse one, lose time with the other.
In order to maximize performance within uniquely difficult logistical and regulatory conditions, the Aston Martin Red Bull Racing team has had to deploy a very powerful and agile IT estate.
According to Neil Bailey, Head of IT Infrastructure, Enterprise Architecture and Innovation, their legacy trackside infrastructure was “creaking”. Before choosing hyperconverged infrastructure, their “traditional IT had reached its limits”, says Bailey. “When things reach their limits they break, just like a car,” adds Bailey.
The team’s biggest emphasis for switching to HPE’s hyperconverged infrastructure, SimpliVity, was performance. Now, with “the extra performance of SimpliVity, it means it doesn’t get to its limits,” says Bailey. HPE SimpliVity has helped reduce space, has optimized processing power and brought more agility.
One of the first and most important use cases they switched to hyperconverged infrastructure was post-processing trackside data. During a race weekend each car is typically fitted with over 100 sensors providing key data on things like tyre temperature and downforce multiple times per second. Processing this data and acting on the insights is key to driving performance improvements. With their legacy infrastructure, Bailey says they were “losing valuable track time during free practice waiting for data processing to take place.” Since switching to HPE SimpliVity, data processing has dropped from being more than 15 minutes to less than 5 minutes. Overall, the team has seen a 79% performance boost compared to the legacy architecture. This has allowed for real time race strategy analysis and has improved race strategy decision making.
Data insights helps the team stay one step ahead, as race strategy decisions are data driven. For example, real time tyre temperature data helps the team judge tyre wear and make pit stop decisions. Real time access to tyre data helped the team to victory at the 2018 Chinese Grand Prix as the Aston Martin Red Bull cars pitted ahead of the rest of the field and Daniel Ricciardo swept to a memorable victory.
Hyperconverged infrastructure is also well suited to the “hostile” trackside environment, according to Bailey. With hyperconverged infrastructure, only two racks are needed at each race of which SimpliVity only takes up about 20% of the space, thus freeing up key space in very restricted trackside garages. Furthermore, with the team limited to 60 staff at each race, only two of Bailey’s team can travel. The reduction in equipment and closer integration of HPE SimpliVity means engineers can get the trackside data center up and running quickly and allow trackside staff to start work as soon as they arrive.
Since seeing the notable performance gains from using hyperconverged infrastructure for trackside data processing, the team has also transitioned some of the factory’s IT estate over to HPE SimpliVity. This includes: Aerodynamic metrics, ERP system, SQL server, exchange server and the team’s software house, the Team Foundation Server.
As well as seeing huge performance benefits, HPE SimpliVity has significantly impacted the work patterns of Bailey’s team of just ten. According to Bailey, the biggest operational win from hyperconverged infrastructure is “freeing up engineers’ time from focusing on ‘business as usual’ to innovation.” Traditional IT took up too much of the engineers’ time monitoring systems and just keeping things running. Now with HPE SimpliVity, Bailey’s team can “give the business more and quicker” and “be more creative with how they use technology.”
Hyperconverged infrastructure has given Aston Martin Red Bull Racing the speed, scalability and agility they require without any need to turn to the cloud. It allows them to deliver more and more resources to trackside staff in an increasingly responsive manner. However, even with all these performance gains, Aston Martin Red Bull Racing has been able to reduce IT costs. So, the users are happy, the finance director is happy and the IT team are happy because their jobs are easier. Hyperconvergence is clearly the right choice for the unique challenges of Formula 1 racing.
Big bites from Apple
Apple’s announcement advanced medical features on its new Apple Watch and a more affordable iPhone were the biggest bites from its annual product launch, writes BRYAN TURNER.
Apple’s annual early-September event kicked off with a small advance that could make a big difference: the next iteration of the Apple Watch, Series 4, with the first consumer-facing ECG monitor approved by authorities. While the overall design remains similar to its predecessors, the screen is around 30% larger than the previous version, thanks to a smaller bezel. This resulted in new categories, namely 40mm and 44mm instead of 38mm and 42mm. However, Apple Watch bands from previous generations still work with the new Apple Watch. The screen is also rounded at the corners of the display, instead of being a square display inside rounded glass. Despite all the improvements, it still weighs around 30 grams without the watch band.
The introduction of the first consumer-facing wrist ECG (electrocardiogram) is revolutionary in the wearable space and reaffirms the Apple Watch as a device for the health conscious. The Apple Watch underwent a full internal and external redesign. Internally, the digital crown has been redesigned to be more “clicky”, with haptic feedback, and features a metal tip for use in an ECG measurement. An ECG can be taken when the user completes a circuit by placing the opposite hand’s finger on the metal tip of the digital crown. This is helpful for those who need to know when they are experiencing atrial fibrillation, an irregular beating of the heart. Fall detection has also been implemented, where a user must tap “I’m fine” after a fall, slip or trip. If the Apple Watch is still for a minute after a fall, emergency contacts are notified with a fall message and location.
Next up, the iPhone line was given an update instead of an upgrade with the iPhone XS. Last year broke the 8-year “major iPhone version followed by an S version” cycle. Apple opted to skip what would have been the iPhone 7S and released the iPhone 8. Apple also released the iPhone X for its tenth anniversary of releasing iPhones. This year, the S cycle is back. The iPhone XS sends the message that Apple is not currently concerned with cosmetic features and would rather focus on making its flagship smartphones better internally.
The iPhone XS was released in 2 tiers, namely the 5.8″ iPhone XS and the 6.5″ iPhone XS Max. The iPhone XS Max is what we know as the “Plus” range, which features a screen that’s almost an inch bigger diagonally than the iPhone XS and holds the same Super Retina Display specification, around 450 pixels per inch. Internally, the iPhone XS Max is no different from the iPhone XS apart from a larger battery.
Apple’s A12 bionic chip is not the first 7-nanometre chip to be announced in a smartphone (that was Huawei) but will be the first to reach the market. The incredible aspect of the 7nm chip is that it houses 6.9 billion transistors, which allow for 5 trillion operations to be run per second. In addition to this, a Neural Engine allocates all the processes where they fit best, either to the CPU, the GPU or processes quickly itself. This speeds the iPhone XS up by 30% compared to the iPhone X – if you are able to notice such things.
Talking pf which, thanks to the better processor, Face ID performs a lot faster. The neural engine can separate hair from the backgrounds of portrait photos. The XS also has wider stereo sound, thanks to a slight internal speaker readjustment. The screen has been optimised for Dolby Vision and HDR10 which work with the OLED screen to provide vibrant colours and distinct on-screen graphics.
Apple left a surprise for the end of its keynote when CEO Tim Cook introduced the iPhone XR. This iPhone looks and feels like an iPhone XS at first glance, but has been stripped of some features.
It’s interesting that Apple is not repeating its iPhone 5C mistakes with this iPhone. It uses the A12 Bionic, the same processor in the XS line, which means that the cheaper iPhone performs exactly the same as the most expensive one. The XR has an edge-to-edge display with Face ID, like the iPhone XS, but has an LCD screen instead of OLED. This would have reduced Apple’s cost per unitsubstantially. On the back, the XR sports a single camera instead of the dual camera setup in the iPhone XS. However, the iPhone XR can still do portrait mode photos, thanks to the A12 Bionic.
Overall, it may seem as if the Apple Watch stole the show, but Apple no doubt hopes the iPhone XR will convince the market it is an affordable iPhone.