New Research Reveals Fastest Winds Ever Seen

New research led by astrophysicists at York University has revealed the fastest winds ever seen at ultraviolet wavelengths near a supermassive black hole. The team’s findings were published today in the print edition of the Monthly Notices of the Royal Astronomical Society.

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Jesse Rogerson, Department of Physics and Astronomy at York University said; “We’re talking wind speeds of 20 per cent the speed of light, which is more than 200 million kilometers an hour. That’s equivalent to a category 77 hurricane – and we have reason to believe that there are quasar winds that are even faster.”

Astronomers have known about the existence of quasar winds since the late 1960s. At least one in four quasars have them. Quasars are the discs of hot gas that form around supermassive black holes at the center of massive galaxies – they are bigger than Earth’s orbit around the Sun and hotter than the surface of the Sun, generating enough light to be seen across the observable universe.

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“Black holes can have a mass that is billions of times larger than the Sun, mostly because they are messy eaters in a way, capturing any material that ventures too close,” says York University Associate Professor Patrick Hall, who is Rogerson’s supervisor. “But as matter spirals toward a black hole, some of it is blown away by the heat and light of the quasar. These are the winds that we are detecting.”

Rogerson and his team used data from a large survey of the sky known as the Sloan Digital Sky Survey to identify new outflows from quasars. After spotting about 300 examples, they selected about 100 for further exploration, collecting data with the Gemini Observatory’s twin telescopes in Hawaii and Chile, in which Canada has a major share.

“We not only confirmed this fastest-ever ultraviolet wind, but also discovered a new wind in the same quasar moving more slowly, at only 140 million kilometers an hour,” says Hall. “We plan to keep watching this quasar to see what happens next.”

Much of this research is aimed at better understanding outflows from quasars and why they happen.

“Quasar winds play an important role in galaxy formation,” says Rogerson. “When galaxies form, these winds fling material outwards and deter the creation of stars. If such winds didn’t exist or were less powerful, we would see far more stars in big galaxies than we actually do.”

Green Comet Approaches Earth

On March 21st, Comet 252P/LINEAR will make a close approach to Earth–only 0.036 AU (5.4 million km) away. This is the fifth closest cometary approach on record and, as a result, the normally dim comet has become an easy target for backyard telescopes. Indeed, it is brightening much faster than expected.

“Comet 252P/LINEAR has surpassed expectations and is now bordering on naked eye visibility for southern observers,” reports Michael Mattiazzo of Swan Hill, Australia. “At the moment it is near magnitude +6,” Observing from Brisbane, Australia, Tom Harradine didn’t even need a telescope to photograph 252P/LINEAR. On March 17th, he caught the green comet (circled) passing by the Tarantula Nebula using just a digital camera.

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The comet is green because its vaporizing nucleus emits diatomic carbon, C2, a gas which glows green in the near-vacuum of space. The verdant color will become more intense in the nights ahead as 252P/LINEAR approaches Earth.

In recent days, astronomers have realized that Comet 252P/LINEAR might have a companion. A smaller and much dimmer comet named “P/2016 BA14” will buzz Earth even closer than 252P/LINEAR on March 22nd. P/2016 BA14 appears to be a fragment of 252P/LINEAR. Unlike its parent, however, P/2016 BA14 is “pitifully faint” and difficult to observe. Sky and Telescope has the full story.

There is a chance that the comet’s approach could cause a minor meteor shower. According to the International Meteor Organization, “[modeling by forecaster] Mikhail Maslov indicates that there might be a weak episode of faint, very slow meteors (15.5 km/s) on March 28–30 from a radiant near the star μ Leporis.” Little is known about meteors from this comet, so estimates of the meteor rate are very uncertain. Maslov’s models suggest no more than 5 to 10 per hour.

Galactic Cosmic Rays Accelerating to Unprecedented Levels

At the center of the Milky Way, a new discovery reveals for the first time a source of this cosmic radiation at energies never observed before. The center of our galaxy is home to many objects capable of producing cosmic rays of high energy, including, in particular, a supernova remnant, a pulsar wind nebula, and a compact cluster of massive stars.

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Today we know that cosmic rays with energies up to approximately 100 teraelectronvolts (TeV) are produced in our galaxy, by objects such as supernova remnants and pulsar wind nebulae. Theoretical arguments and direct measurements of cosmic rays reaching the Earth indicate, however, that the cosmic-ray factories in our galaxy should be able to provide particles up to one petaelectronvolt (PeV) at least. While many multi-TeV accelerators have been discovered in recent years, the search for the sources of the highest energy galactic cosmic rays has, so far, been unsuccessful.

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However, “the supermassive black hole located at the center of our galaxy Milky Way, called Sgr A*, is the most plausible source of the PeV protons,” says Felix Aharonian (MPIK, Heidelberg and DIAS, Dublin), adding that, “several possible acceleration regions can be considered, either in the immediate vicinity of the black hole, or further away, where a fraction of the material falling into the black hole is ejected back into the environment, thereby initiating the acceleration of particles.”

The (High Energy Stereoscopic System) H.E.S.S. measurement of the gamma-ray emission can be used to infer the spectrum of the protons that have been accelerated by the central black hole – revealing that Sgr A* is very likely accelerating protons to PeV energies. Currently, these protons cannot account for the total flux of cosmic rays detected at the Earth. “If, however, our central black hole was more active in the past,” the scientists argue, “then it could indeed be responsible for the bulk of the galactic cosmic rays that are observed today at the Earth.” If true, this would dramatically influence the century old debate concerning the origin of these enigmatic particles.

BREAKING NEWS: Galactic Cosmic Rays Accelerating to Unprecedented Levels

At the center of the Milky Way, a new discovery reveals for the first time a source of this cosmic radiation at energies never observed before. The center of our galaxy is home to many objects capable of producing cosmic rays of high energy, including, in particular, a supernova remnant, a pulsar wind nebula, and a compact cluster of massive stars.

CREATOR: gd-jpeg v1.0 (using IJG JPEG v62), quality = 75

Today we know that cosmic rays with energies up to approximately 100 teraelectronvolts (TeV) are produced in our galaxy, by objects such as supernova remnants and pulsar wind nebulae. Theoretical arguments and direct measurements of cosmic rays reaching the Earth indicate, however, that the cosmic-ray factories in our galaxy should be able to provide particles up to one petaelectronvolt (PeV) at least. While many multi-TeV accelerators have been discovered in recent years, the search for the sources of the highest energy galactic cosmic rays has, so far, been unsuccessful.

galaxy-center333_mm

However, “the supermassive black hole located at the center of our galaxy Milky Way, called Sgr A*, is the most plausible source of the PeV protons,” says Felix Aharonian (MPIK, Heidelberg and DIAS, Dublin), adding that, “several possible acceleration regions can be considered, either in the immediate vicinity of the black hole, or further away, where a fraction of the material falling into the black hole is ejected back into the environment, thereby initiating the acceleration of particles.”

The (High Energy Stereoscopic System) H.E.S.S. measurement of the gamma-ray emission can be used to infer the spectrum of the protons that have been accelerated by the central black hole – revealing that Sgr A* is very likely accelerating protons to PeV energies. Currently, these protons cannot account for the total flux of cosmic rays detected at the Earth. “If, however, our central black hole was more active in the past,” the scientists argue, “then it could indeed be responsible for the bulk of the galactic cosmic rays that are observed today at the Earth.” If true, this would dramatically influence the century old debate concerning the origin of these enigmatic particles.

Amateur Metal Detector Finds Ancient Crucifix – May Change Historical Record

An amateur metal detector has made a discovery that experts think could change our understanding of Christianity in Denmark.

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Dennis Fabricius Holm was enjoying an afternoon off work when he found a Birka crucifix pendant in a field near the town of Aunslev, Østfyn.

“I got off early on Friday, so I took just a few hours, I went around with my metal detector and then I came suddenly on something,” Mr Holm told DK.

“Since I cleared the mud and saw the jewelry, I have not been able to think of anything else.”

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On posting the find to social media, other users encouraged him to take it to a museum.

Malene Refshauge Beck, curator and archaeologist at Østfyns Museum said: “It is an absolutely sensational discovery that is from the first half of the 900s [10th century].”

“There is found an almost identical figure in Sweden, which has been dated to just this period.”

However, this specimen is in especially good condition and one of the most well preserved Christian artifacts found in Denmark.

Weighing just 13.2 grams and 4.1cm in length, the figure is made of finely articulated goldthreads and tiny filigree pellets.

It is smooth on the reverse side but has a small eye at the top for a chain.

It was probably worn by a Viking woman.

The dating of the crucifix, estimated at being from 900 – 950AD, is significant because it would indicate Danes embraced Christianity earlier than previously thought.

At the moment, the Jelling Stones – two large rune-stones erected in 965AD in Jutland – are thought to be the oldest known representation of Jesus on a cross in Denmark.

The stones, in the town of Jelling, commemorate Harald Bluetooth’s conversion of the Danes to Christianity.

Christian missionaries had been present in the country for around two hundred years before then, but had failed to convert the Vikings.

However, pressures from Christian trade partners to convert, and in particular, influence from the Kingdom of Germany to the south, meant that most Danes were Christian by the end of the Viking period in 1050.

“The figure can therefore help to advance the time when one considers that the Danes really were Christians,” said Ms Beck.

“Simply because one can say that the person who carried it here no doubt embraced the Christian faith.”

The impact of the find is such that the historical record of the country will need to be adjusted.

“This is a subject that certainly will have to appear in the history books in the future,” said Ms Beck.

“In recent years there has been more and more signs that Christianity was widespread earlier than previously thought – and here the clearest evidence so far.”

 

UPDATE: Comet Flyby Mars’ Magnetic Field and Charged Particles

Jared Espley, a MAVEN science team member at NASA’s Goddard Space Flight Center said; “Comet Siding Spring plunged the magnetic field around Mars into chaos. We think the encounter blew away part of Mars’ upper atmosphere, much like a strong solar storm would.”

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Mars’ atmosphere was very much like Earth’s – that is until an interplanetary collision occurred ripping its protective magnetic field away. However, some managed to remain after the event, additionally; current seasonal climate change continues to produce upper atmospheric plasma which is in fact charged particles.

Comet Siding Spring is also surrounded by a magnetic field as a result of solar wind interacting with plasma generated in the coma, which is the large mass we see as a gaseous cloud. Comet Siding Spring’s nucleus, as are all comets, just a tiny asteroid with remaining ice. In this case, its nucleus is approximately .3 miles (.5 km) in diameter. However, the coma, as with all comets, stretches some 600,000 miles (1,000,000 km) in distance.

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As a result of Earth’s magnetic field weakening with increasing amounts each year, it is time to reconsider the effects of NEOs (Near Earth Orbits). Comets create their own atmosphere by outgassing which contributes to its generating of charged particles. What is less known, is that although asteroids do not have an atmosphere, they do retain predominantly positively charged cosmic rays. They would mostly burnout during entry through Earth’s atmosphere, but as we know, the large ones make it through.

But it is time to recalibrate. Due to a weakening magnetic field, it might be wise to view the small guys with a little more interest and be a little less ambivalent when we hear the newscaster say in their jocular playful manner: “hey, did you hear about the near miss we had last night….

Red Sprites At The Edge Of Space

Solar activity is very low. Nevertheless, space weather continues. High above late-summer thunderstorms in Africa, red sprites are dancing across the cloudtops, reaching up to the edge of space itself. Astronauts onboard the International Space Station photographed this specimen (circled) on March 14th.

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Sprites are an exotic form of “upward lightning.” They are a true space weather phenomenon, inhabiting the upper reaches of Earth’s atmosphere alongside meteors, and some auroras. Some researchers believe sprites are linked to cosmic rays: subatomic particles from deep space striking the top of Earth’s atmosphere produce secondary electrons that, in turn, could provide the spark that triggers the elaborate red forms.

Although sprites have been seen for at least a century, most scientists did not believe they existed until after 1989 when sprites were photographed by cameras onboard the space shuttle. They have since been photographed many times from the ISS.