Tuesday, April 29, 2008
Intel is to embark on a partnership programme with supercomputing specialist Cray Systems.
The two companies will develop the main components for a new generation of supercomputers using multi-core chips and advanced interconnection methods.
The new systems will be targeted at traditional supercomputing markets, such as engineering calculations and scientific modelling and analysis.
Cray president and chief executive Peter Ungaro said: "This collaboration provides the HPC market segment with access to the best microprocessors the industry has to offer at any point in time, in the most advanced supercomputers in the world."
The two companies expect the initiative to bear fruit in 2010, when Cray plans to ship the first of its Cascade line of supercomputers.
The Cascade project, which is partially backed by a grant from the US Defense Advanced Research Projects Agency, is an attempt to use multiple processor types and computing methods in a 'hybrid' supercomputer.
The move also marks a win for Intel. Cray had originally planned to base Cascade on chips from rival vendor AMD.
Shares of supercomputer maker Cray Inc. rose Monday after an analyst upgraded the supercomputer maker, citing greater chip availability from Advanced Micro Devices Inc.
The Seattle-based company's stock rose 48 cents, or 7.6 percent, to $6.83.
Northland Securities analyst Chad Bennett raised his rating to "Outperform" from "Market Perform" and kept a $9 price target. The target implies he expects the stock to rise about 42 percent over Friday's $6.35 close.
Bennett said news from AMD that it will begin shipping a type of core semiconductor gives him "increasing comfort" on chip supply.
The company is set to post first-quarter results on Tuesday, but Bennett said investors should look at the rest of the year, especially after the AMD news.
HOW can Grand Theft Auto IV ever live up to the expectations bestowed upon it? From its first unveiling over a year ago, hype levels have been steadily escalating towards the stratosphere, and surely it would be impossible for Rockstar to satiate the lust of those deprived of a fresh Grand Theft Auto experience for nearly four years?
It's clear that this iteration of Grand Theft Auto is a markedly different beast to its predecessor San Andreas, and whatever your feelings about the last outing there's no doubting the series' new direction works towards creating a more immersive experience. Nearly all vestiges of videogame signifiers have been shorn away and for once it's perfectly valid to state that playing the game is akin to watching a cinema blockbuster. The HUD has been refined, appearing only when Niko is engaged in action, and the omnipresent map at the bottom left of the screen is often all that remains to remind onlookers that this is an interactive entertainment.
Videogame artefacts such as hidden packages have been omitted – though those who have a fetish for collecting need not worry, as in their place is a series of collectables of a more naturalised manner - and the jumps that have long marked out the Grand Theft Auto games are more subtly implemented. Indeed, it was only after a few hours play that we realised they were still there, so well camouflaged they were amidst the architecture of Liberty City.
And what a creation the city is. Grand Theft Auto IV's Liberty City is one of the finest worlds we've seen in gaming since we gallivanted around the Hyrule of Ocarina of Time. It's a world that lives and breathes with its own authenticity, and with an effortlessness that has rarely been glimpsed in gaming to date. A storm comes in and the lighting engine paints the streets of Broker with a melancholic taint, with passers-by erecting their umbrellas in the downpour and those more ill prepared raise their suitcases above their heads and run for cover, while in the background a lone saxophonist plays under the shelter of a band stand. The sun shines and the streets burst into life, light rays bouncing off the pavement and glistening over the bonnets of traffic. The level of detail informs every aspect of Liberty City, with even the most secluded alleyway exuding its own atmosphere and conspiring to make Grand Theft Auto IV's world one of the most complete witnessed to date.
This whole world is painted with its own distinct perspective - yes, this is a more realistic Grand Theft Auto than ever before, but it's also one of the most stylised entries, with a filter applied to the graphics attaining an effect that's akin to pointillism and at times can seem almost impressionistic. That's not to say there aren't occasional dips in framerate or texture creep, but none of this ever impinges on what is undoubtedly one of the most achingly beautiful videogame creations to date.
Above all it's a gritty creation, with the more down to earth and grimy nature of Niko's story reflected in each brick that builds Liberty City. At the beginning of the game, when confined to the Broker District by a terrorist threat, Niko can take a peek at what lies ahead of him in his quest, his view of the peaks of the skyscrapers of Algonquin filtered through the dirt of Liberty City that blights the lens. These details stretch to the interiors as well – this is a world of squalor, and no more is that evident than when climbing a flight of stairs to Niko's first abode in the slums of Broker, the strip lights humming and a muffled television audible through the door of a neighbouring flat.
This Liberty City is unmistakably a mirror image of contemporary New York, and with this fresh focus Rockstar has delivered one of its most potent satires yet. From the terrorist alert that initially locks down the city to the feeds from Weasel News that beautifully ape a certain real-life feral news service reporting on Niko's more outlandish escapades, to the mayoral election that is so brutally fought out over the airwaves between the fictional Michael Graves and John Hunter, it's never too difficult to ascertain the real-life sources for Grand Theft Auto IV's swipes.
Spyware targets frustrated GTA IV gamers
Gamers desperate to get their mitts on Grand Theft Auto IV are being targeted in an opportunistic spyware scam. Spam emails offer prospective marks free entry to a draw offering a PlayStation 3 loaded with the much-anticipated game as a prize.
In reality, these illicit emails are loaded with spyware designed to swipe personal financial information from compromised PCs.
Grand Theft Auto IV for the PS3 and the Xbox 360 was released today to delirium from avid gamers. But some wouldbe buyers have been left disappointed as game stores have been unable to fulfill demand to the extent that even a minority of fans who pre-ordered the game have been left empty-handed.
Spammers are seeking to exploit this disappointment with a carefully targeted spam scam.
Consumer-focused spam filtering firm ClearMyMail claims that more than half of the junk mail being blocked by its service on Tuesday is Grand Theft Auto IV-related. The vast majority of the junk mail messages offer the opportunity to win a PlS3 complete with the game.
"We are seeing unprecedented levels of spam in relation to the game; with more than half of the spam our service is blocking relating to Grand Theft Auto, most of which contain viruses and spyware," said Dan Field, Managing Director of www.ClearMyMail.com. Field advised keen gamers to wait until they can legitimately purchase the game rather than fall victim to "opportunists" capitalising on pent-up demand.
Stuart Rowe, chief operating officer at online retailer Play.com, said the game has created unprecedented demand. "We're experiencing trading levels similar to what we would see in the run up to Christmas, taking over 80 orders per minute at peak times," he said. "We have had to recruit extra warehouse staff to work through the night to ensure product arrives on the day of launch." ®
Google engineers last week presented an interesting paper at the WWW2008 conference in Beijing which proposes to apply its PageRank system of finding relevant Web pages to radically improve the accuracy of image search results using Google. This new technology is being called VisualRank, according to an fascinating story on the subject in the New York Times.
The paper, titled "PageRank for Product Image Search," (PDF) was published by Yushi Jing and Shumeet Baluja of Google. In it they talk about using PageRank to analyze the "visual link structure" that can be created among a group of similar images. This paper proposes to move away from the current model of many image search engine rankings, described as using "the text clues of the pages in which images are embedded to rank images."
The new model would "identify 'authority' nodes on an inferred visual similarity graph and propose an algorithm to analyze the visual link structure that can be created among a group of images." A numerical weight would be assigned to each image and, according to the paper, ranking would occur based upon "expected user behavior given the visual similarities of the images to be ranked." The assumption, this blog points out, is that "people are more likely to go from an image to other similar images."
Nearly a decade ago, Google unveiled an algorithm called PageRank, reinventing the way we search for web pages. Now, the company says, it has a technology that can do much the same for online image search.
Last week, at the International World Wide Web Conference in Beijing, two Google-affiliated researchers presented a paper called "PageRank for Product Image Search," trumpeting a fledging algorithm that overhauls the primitive text-based methods used by the company's current image search technologies.
Of course, the most recent Google Image Search results are often rubbish. Currently, when ranking images, the big search engines spend little time examining the images themselves. Instead, they look at the text surrounding those images.
By contrast, Google's PageRank for Product Image Search - also known as "VisualRank" - seeks to actually understand what's pictured. But the technology goes beyond classic image recognition, which can be time consuming and/or expensive - and which often breaks down with anything other than faces and a handful of other image types. In an effort to properly identify a wider range of objects, Baluja and Jing have merged existing image processing techniques with the sort of "link analysis" made famous by PageRank.
"Through an iterative procedure based on the PageRank computation, a numerical weight is assigned to each image," they explain. "This measures its relative importance to the other images being considered."
With classic image recognition, you typically take a known image and compare it to other images. You might use a known photo of Paris Hilton, for instance, to find other Paris pics. But VisualRank takes a different tack. Google's algorithm looks for "visual themes" across a collection of images, before ranking each image based on how well it matches those themes.
As an example, the researchers point to an image search on the word "McDonald's." In this case, VisualRank might identify the famous golden arches as theme. An image dominated by the golden arches would then be ranked higher than a pic where the arches are tucked into the background.
Baluja and Jing recently tested their algorithm using images retrieved by Google's 2000 most popular product searches, and a panel of 150 people decided that VisualRank reduced the number of irrelevant results by 83 per cent. The question is whether this could be applied to Google's entire database of images.
At the moment, this is just a research paper. And Google isn't the first to toy with the idea of true image search. After launching an online photo sharing tool that included face and character recognition, the Silicon Valley based Riya is now offering an image-rec shopping engine, known as Like.com, that locates products on sale across the web. And the transatlantic image rec gurus at Blinkx are well on their way with video search. ®
Starting at $1,199, the 24-inch system features a slew of other features, including built-in AirPort Extreme 802.11n Wi-Fi, Bluetooth 2.1+EDR, Gigabit Ethernet, an iSight video camera, USB 2.0 ports, and a FireWire 400 and FireWire 800 port. On the software side of the equation, each new iMac ships with the iLife suite and OS 10.5 Leopard.
The iMac's "aluminum and glass all-in-one design has been an incredible hit with our customers and is just one of the reasons Mac sales are growing three and a half times faster than PC sales," Philip Schiller, the company's senior vice president of worldwide product marketing, said in a statement. "With the latest Intel processors, a faster new graphics option and more memory, customers now have even more reasons to love the iMac."
Apple is also touting the new iMac's environmental friendliness. The system is composed of "highly recyclable and durable materials including scratch-resistant glass and professional grade aluminum," Apple said. Each entry into the line is rated EPEAT Silver and meets Energy Star's new 4.0 power consumption requirements. The company is also offering free recycling of old Macs and PCs, with their Apple Recycling program.
The new models are available now through Apple's retail and online stores. Prices start at $1,199 for the 20-inch 2.4 GHz iMac. The 20-inch 2.66 GHz iMac will go for $1,499, and the 24-inch 2.8 GHz iMac for $1,799
Yesterday’s refresh of the iMac line is interesting, not because of the bump in speed that the refresh itself offers but because of the direction that Apple is going in. Is Apple preparing the way for gaming on the Mac?
First, let’s look closer at that 3.06GHz processor option for the 24-inch iMac. Some of you might be wondering what that processor is. Well, I can tell you now that it’s not an early incarnation of the Centrino 2 technology as some have suggested. It’s a special run on an existing CPU overclocked to handle the 3.06GHz workload and 1,066MHz. It’s definitely hosted on a Santa Rosa motherboard (the Intel GM965 northbridge and ICH8 southbridge gives that away). Apple’s working the current technology hard to get 3.06GHz out of something designed to give 2.8GHz here. Why?
Then there’s the GPU. This seems to be a stock nVIDIA 8800M GTS (even though Apple calls it an 8800 GS, but then again, Apple called Mobility HD 2600 XT parts HD 2600 Pro). This is a high-end GPU and certainly offers far more power than most Mac users currently need from the iMac.
Putting the overclocked processor and a high-end nVIDIA GPU in a box makes this system look like a gaming system to me. Sure, Apple is constrained by its use of mobile parts in the iMac, but the company does seem intent on squeezing as much power as it can out of the components.
Whether Apple is starting to cater for gamers using Boot Camp, or Apple is preparing the way for Mac OS X-based gaming I’m not sure, but either way it looks to me like Apple is getting into gaming. And why not, it’s a lucrative market!
Nanoengineered barrier invented to protect plastic electronics from water degradation
A breakthrough barrier technology from Singapore A*STAR's Institute of Materials Research and Engineering (IMRE) protects sensitive devices like organic light emitting diodes (OLEDs) and solar cells from moisture 1000 times more effectively than any other technology available in the market, opening up new opportunities for the up-and-coming plastic electronics sector.
A team of scientists from Singapore's Institute of Materials Research and Engineering (IMRE) has developed a new patented film that has the highest reported water vapour barrier performance to date, as tested by the UK Centre for Process Innovation.
The tests have shown that the new film is 1,000 times more impervious to moisture than existing technologies. This means a longer lifetime for plastic electronic devices such as solar cells and flexible displays that use these high-end films but whose sensitive organic materials are easily degraded by water vapour and oxygen.
The new technology is a boon to the burgeoning plastic electronics industry that aims to deliver flexible, lightweight and cheap electronics products to consumers in ways that silicon electronics may never reach such as disposable or wraparound displays, cheap identification tags, low cost solar cells and chemical and pressure sensitive sensors.
A research institute of the Singapore's Agency of Science, Technology and Research (A*STAR), IMRE's breakthrough technology comes as Singapore seeks to jumpstart a plastic electronics industry locally as part of the country's long-term plan to anchor new knowledge-intensive industries in the economy.
The global plastic electronics industry is projected to grow to a market size of more than US$23 billion in the next 5 years .
The performance of devices like organic light emitting diodes (OLEDs) and solar cells is sensitive to moisture because water and oxygen molecules seep past the protective plastic layer over time and degrades the organic materials which form the core of these products.
Current commercially available films used to protect these materials have a barrier property or water vapour transmission rate of about 10-3g/m2 per day, or one thousandth of a gram per square meter per day at 25°C and 90% relative humidity (RH).
However, the ideal film for organic devices would require a barrier property of better than 10-6g/m2/day at 39°C and 90% RH, or one millionth of a gram per square meter per day.
Defects such as pinholes, cracks and grain boundaries are common in thin oxide barrier films when fabricated onto plastic substrates. These defects cause a 'pore effect', where oxygen and water molecules are able to seep through and penetrate the plastic barrier.
Current barrier technologies focus on reducing these defects by using alternate organic and inorganic multi-layers coated on plastic. These multiple layers "stagger" corresponding pores in adjacent layers and create a 'tortuous', lengthy pathway for water and oxygen molecules, making it more difficult to travel through the plastic.
In contrast, IMRE has taken an innovative approach to resolve the 'pore effect' by literally plugging the defects in the barrier oxide films using nanoparticles. This reduces the number of barrier layers needed in the construction of the barrier film down to two layers in this unique nanoengineered barrier stack. IMRE's barrier stack consists of barrier oxide layers and nanoparticulate sealing layers.
The nanoparticles used in the barrier film have a dual function - not only sealing the defects but also actively reacting with and retaining moisture and oxygen.
The result is a breakthrough moisture barrier performance of better than 10-6g/m2/day, or one millionth of a gram per square meter per day, which surpasses the requirements for flexible organic device substrates.
The barrier film also has a lag time of more than 2300 hours at 60°C and 90% RH (i.e. the time required for moisture to pass through the barrier film under those conditions).
These plastic barrier properties were tested and validated by the Centre for Process Innovation, UK.
"With a level of protection that surpasses the ideal requirements for such films to date, manufacturers now have the opportunity to extend the lifetime of plastic electronic devices by leaps and bounds!," says Senthil Ramadas, principal investigator of the project.
stumbling block in developing ultra-high barrier substrates has been the availability of an appropriate testing methodology.
Overcoming this hurdle, the IMRE project team has developed a highly sensitive moisture and oxygen permeation measurement system in tandem with the development of the film which is able to effectively measure permeation of less than 10-8g/m2/day. This system has been successfully implemented in a number of service based industry projects.
Adds Senthil, "Together with our expertise in encapsulation processes and permeation measurement technologies we are also able to provide a total solution package for industries such as flexible solar cells and OLED displays producers".
Recognising the potential of the high performance substrate technology, Exploit Technologies Pte Ltd (ETPL), the commercialisation arm of A*STAR, has funded the team through a 'flagship project' that seeks out research with excellent commercialisation potential.
Boon Swan Foo, the Executive Chairman of ETPL said, "Exploit Technologies sees commercial potential in A*STAR IMRE's breakthrough barrier film technology. It has excellent promise for enabling the fast growing plastic electronics industry. We want to take this technology from the lab to the market."
"The research team is already in talks with solar cells and flexible displays and lighting industry manufacturers who are currently evaluating the barrier films for product qualification", says Dr. Mark Auch, a member of the IMRE team who is actively involved in the commercialization of the technology.
IMRE has already signed agreements with a number of companies to advance the technology into the commercial domain. This includes a collaboration agreement with G24Innovations, a thin film solar cell manufacturer to look into developing the films for use in solar cells.
Clemens Betzel, the president of G24Innovations, who was in Singapore for the signing of the cooperation agreement, said, "The cutting edge work of IMRE's Barrier Substrates is likely to mean significant progress for Dye Sensitized Solar Cells, as exclusively manufactured today by G24I. We are looking forward to broadening our relationship with IMRE in the coming months."
IMRE has also signed a commercialisation agreement with KISCO (Asia), a subsidiary of the Japanese parent company KISCO Ltd., to commercialise and market the barrier films in the Asia Pacific region.
"We have a long-standing research relationship with IMRE and are very familiar with their work. We have high confidence in the quality of IMRE's barrier films and we believe, that this partnership will be beneficial to both parties," says Albin Tan, General Manager of KISCO (Asia), Singapore.
Current barriers have a series of alternating polymer and metal oxide layers that make up the plastic. This staggers adjacent 'pinholes', natural defects in the layers, thus slowing the passage of moisture and air through the 'pinholes'.
The secret behind the effectiveness of IMRE's technology lies in the unique barrier stack design, where nanoparticles are used when layering the barrier films. The design has a special layer of nanoparticles between the "pinhole" oxide layers. The innovativeness becomes clear as the nanoparticles "plug" the gaps and cracks in the oxide layer thus making for a more impermeable layer. In addition to sealing of oxide barrier film's defects, the nanoparticles absorb and retain the water and oxygen molecules. This concept helps reduce the number of barrier stacks to two or three only.
IMRE has successfully resolved the 'pore effect issue' in multi-layered barrier stacks and developed ultra high barrier plastic substrates (barrier properties < 10-6 g/m2/day) for high barrier applications. Our calcium test results show that there is no calcium oxidation up to 2300hrs at 60°C and 90% relative humidity.
Source: Agency for Science, Technology and Research (A*STAR), Singapore
Biodesign Institute scientist John Chaput and his research team have made the first self-assembled nanostructures composed entirely of glycerol nucleic acid -- a synthetic analog of DNA. The nanostructures contain additional properties not found in natural DNA, including the ability to form mirror image structures. The ability to make mirror image structures opens up new possibilities for nanotechnology. Credit: Biodesign Institute at Arizona State University
Scientists make chemical cousin of DNA for use as new nanotechnology building block
In the rapid and fast-growing world of nanotechnology, researchers are continually on the lookout for new building blocks to push innovation and discovery to scales much smaller than the tiniest speck of dust.
at this scale holds great potential for advancing medical and electronic applications. DNA, often thought of as the molecule of life, is an ideal building block for nanotechnology because they self-assemble, snapping together into shapes based on natural chemical rules of attraction. This is a major advantage for Biodesign researchers like Hao Yan, who rely on the unique chemical and physical properties of DNA to make their complex nanostructures.
While scientists are fully exploring the promise of DNA nanotechnology, Biodesign Institute colleague John Chaput is working to give researchers brand new materials to aid their designs. In an article recently published in the Journal of the American Chemical Society, Chaput and his research team have made the first self-assembled nanostructures composed entirely of glycerol nucleic acid (GNA)-a synthetic analog of DNA.
"Everyone in DNA nanotechnology is essentially limited by what they can buy off the shelf," said Chaput, who is also an ASU assistant professor in the Department of Chemistry and Biochemistry. "We wanted to build synthetic molecules that assembled like DNA, but had additional properties not found in natural DNA."
The DNA helix is made up of just three simple parts: a sugar and a phosphate molecule that form the backbone of the DNA ladder, and one of four nitrogenous bases that make up the rungs. The nitrogenous base pairing rules in the DNA chemical alphabet fold DNA into a variety of useful shapes for nanotechnology, given that "A" can only form a zipper-like chemical bond with "T" and "G" only pair with "C."
In the case of GNA, the sugar is the only difference with DNA. The five carbon sugar commonly found in DNA, called deoxyribose, is substituted by glycerol, which contains just three carbon atoms.
Chaput has had a long-standing interest in tinkering with chemical building blocks used to make molecules like proteins and nucleic acids that do not exist in nature. When it came time to synthesize the first self-assembled GNA nanostructures, Chaput had to go back to basics. "The idea behind the research was what to start with a simple DNA nanostructure that we could just mimic."
The first self-assembled DNA nanostructure was made by Ned Seeman's lab at Columbia University in 1998, the very same laboratory where ASU professor Hao Yan received his Ph.D. Chaput's team, which includes graduate students Richard Zhang and Elizabeth McCullum were not only able to duplicate these structures, but, unique to GNA, found they could make mirror image nanostructures.
In nature, many molecules important to life like DNA and proteins have evolved to exist only as right-handed. The GNA structures, unlike DNA, turned out to be 'enantiomeric' molecules, which in chemical terms means both left and right-handed.
"Making GNA is not tricky, it's just three steps, and with three carbon atoms, only one stereo center," said Chaput. "It allows us to make these right and left-handed biomolecules. People have actually made left-handed DNA, but it is a synthetic nightmare. To use it for DNA nanotechnology could never work. It's too high of a cost to make, so one could never get enough material."
The ability to make mirror image structures opens up new possibilities for making nanostructures. The research team also found a number of physical and chemical properties that were unique to GNA, including having a higher tolerance to heat than DNA nanostructures. Now, with a new material in hand, which Chaput dubs 'unnatural nucleic acid nanostructures,' the group hopes to explore the limits on the topology and types of structure they can make.
"We think we can take this as a basic building block and begin to build more elaborate structures in 2-D and see them in atomic force microscopy images," said Chaput. "I think it will be interesting to see where it will all go. Researchers come up with all of these clever designs now."
Scientists study evidence modern birds came from dinosaurs
It looks like chickens deserve more respect. Scientists are fleshing out the proof that today's broiler-fryer is descended from the mighty Tyrannosaurus rex. And, not a surprise, they confirmed a close relationship between mastodons and elephants.
Fossil studies have long suggested modern birds were descended from T. rex, based in similarities in their skeletons.
Now, bits of protein obtained from connective tissues in a T. rex fossil shows a relationship to birds including chickens and ostriches, according to a report in Friday's edition of the journal Science.
"These results match predictions made from skeletal anatomy, providing the first molecular evidence for the evolutionary relationships of a non-avian dinosaur," Chris Organ, a postdoctoral researcher in biology at Harvard University said in a statement.
Co-author John M. Asara of Harvard reported last year that his team had been able to extract collagen from a T. rex and that it most closely resembled the collagen of chickens.
They weren't able to recover dinosaur DNA, the genetic instructions for life, but DNA codes for the proteins they did study.
While the researchers were able to obtain just a few proteins from T. rex, they have now been able to show the relationships with birds.
With more data, Organ said, they would probably be able to place T. rex on the evolutionary tree between alligators and chickens and ostriches.
"We also show that it groups better with birds than modern reptiles, such as alligators and green anole lizards," Asara added.
The dinosaur protein was obtained a fossil found in 2003 by John Horner of the Museum of the Rockies in a barren fossil-rich stretch of land that spans Wyoming and Montana. Mary H. Schweitzer of North Carolina State University and the North Carolina Museum of Natural Sciences discovered soft-tissue preservation in the T. rex bone in 2005.
The research of Organ and Asara indicates that the protein from the fossilized tissue is authentic, rather than contamination from a living species.
The researchers also studied material recovered from a mastodon fossil and determined it was related to modern elephants.
Their research was funded by the National Institutes of Health, National Science Foundation, Paul F. Glenn Foundation and the David and Lucille Packard Foundation.
Meanwhile, in another paper in Science, researchers report refining a method to determine ancient dates that will allow them to better pinpoint events such as dinosaurs' extinction.
A team led by Paul Renne, director of the Berkeley Geochronology Center and an adjunct professor of earth and planetary science at the University of California, Berkeley, said they were able to refine the so-called argon-argon dating method to reduce uncertainty. The method compares the ratio or two types of the element argon found in rocks.
The greater precision matters little for recent events in the last few million years, according to Renne, but it can be a major problem for events in the early solar system. For example, a one percent difference at 4.5 billion years is almost 50 million years.
The new system reduces that potential uncertainty to one-fourth of one percent, the researchers said.
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Astronomers get closer view of black hole jet
While we may never know what it looks like inside a black hole, astronomers recently obtained one of the closest views yet. The sighting allowed scientists to confirm theories about how these giant cosmic sinkholes spew out jets of particles travelling at nearly the speed of light.
Ever since the first observations of these powerful jets, which are among the brightest objects seen in the universe, astronomers have wondered what causes the particles to accelerate to such great speeds. A leading hypothesis suggested the black hole's gigantic mass distorts space and time around it, twisting magnetic field lines into a coil that propels material outward.
Now researchers have observed a jet during a period of extreme outburst and found evidence that streams of particles wind a corkscrew path away from the black hole, as the leading hypothesis predicts.
"We got an unprecedented view of the inner portion of one of these jets and gained information that's very important to understanding how these tremendous particle accelerators work," said Boston University astronomer Alan Marscher, who led the research team. The results of the study are detailed in the April 24 issue of the journal Nature.
The team studied a galaxy called BL Lacertae (BL Lac), about 950 million light years from Earth, with a central black hole containing 200 million times the mass of our Sun. Since this supermassive black hole's jets are pointing nearly straight at us, it is called a blazar (a quasar is often thought to be the same as a blazar, except its jets are pointed away from us).
The new observations, taken by the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope, along with NASA's Rossi X-ray Timing Explorer and a number of optical telescopes, show material moving outward along a spiral channel, as the scientists expected.
These data support the suggestion that twisted magnetic field lines are creating the jet plumes. Material in the center of the galaxy, such as nearby stars and gas, gets pulled in by the black hole's overwhelming gravity and forms a disk orbiting around the core (the material's inertia keeps it spiraling in a disk rather than falling straight into the black hole). The distorted magnetic field lines seem to pull charged particles off the disk and cause them to gush outward at nearly the speed of light.
"We knew that material was falling in to these regions, and we knew that there were outbursts coming out," said University of Michigan astronomer Hugh Aller, who worked on the new study. "What's really been a mystery was that we could see there were these really high-energy particles, but we didn't know how they were created, how they were accelerated. It turns out that the model matches the data. We can actually see the particles gaining velocity as they are accelerated along this magnetic field."
The astronomers also observed evidence of another phenomenon predicted by the leading hypothesis - that a flare would be produced when material spewing out in the jets hit a shock wave beyond the core of the black hole.
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