Burst of Galactic Cosmic Rays Produces Crack in Earth’s Magnetic Field

The world’s largest and most sensitive cosmic ray monitor, located in India, has recorded a burst of galactic cosmic rays which produced a crack in the Earth’s magnetic shield, according to scientists.

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This is to say, a large fast moving coronal mass ejection (CME) from our Sun acting as an offensive front line making an opening in Earth’s magnetic field which then allowed an unusual large flow of galactic cosmic rays (GCR) to enter our atmosphere.

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This event is unusual due to the fact that during times of high solar activity, the larger solar particles push aside the smaller but more harmful and damaging cosmic rays particles which produce high levels of radiation. Galactic cosmic rays come from outside our solar system generated from various celestial events such as exploding stars or supernovas occurring throughout our galaxy Milky Way.

The GRAPES-3 muon telescope located at the Tata Institute of Fundamental Research’s Cosmic Ray Laboratory in Ooty recorded a burst of galactic cosmic rays last year lasting for two hours.

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The burst occurred when a giant cloud of plasma ejected from the solar corona, and moving with a speed of about 1.56 million per hour (2.5 million km) struck our planet, causing a severe compression of Earth’s magnetosphere from 11 to 4 times the radius of Earth. It triggered a severe geomagnetic storm that generated aurora borealis and radio signal blackouts in many high latitude countries, according to the study published in the journal Physical Review Letters this week.

Earth’s magnetosphere extends over a radius of 620,000 miles (1,000,000,000 kilometers), which acts as the first line of defense, shielding us from the continuous flow of solar and galactic cosmic rays, thus protecting life on our planet from these high intensity energetic radiations.

Detour Via Gravitational Lens Makes Distant Galaxy Visible

Never before have astrophysicists measured light of such high energy from a celestial object so far away. Around 7 billion years ago, a huge explosion occurred at the black hole in the center of a galaxy. This was followed by a burst of high-intensity gamma rays. A number of telescopes, MAGIC included, have succeeded in capturing this light. An added bonus: it was thus possible to reconfirm Einstein’s General Theory of Relativity, as the light rays encountered a less distant galaxy en route to Earth — and were deflected by this so-called gravitational lens.

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The object QSO B0218+357 is a blazar, a specific type of black hole. Researchers now assume that there is a supermassive black hole at the center of every galaxy. Black holes, into which matter is currently plunging are called active black holes. They emit extremely bright jets. If these bursts point towards Earth, the term blazar is used.

Full moon prevents the first MAGIC observation

The event now described in “Astronomy & Astrophysics” took place 7 billion years ago, when the universe was not even half its present age. “The blazar was discovered initially on 14 July 2014 by the Large Area Telescope (LAT) of the Fermi satellite,” explains Razmik Mirzoyan, scientist at the Max Planck Institute for Physics and spokesperson for the MAGIC collaboration. “The gamma ray telescopes on Earth immediately fixed their sights on the blazer in order to learn more about this object.”

One of these telescopes was MAGIC, on the Canary Island of La Palma, specialized in high-energy gamma rays. It can capture photons — light particles — whose energy is 100 billion times higher than the photons emitted by our Sun and a thousand times higher than those measured by Fermi-LAT. The MAGIC scientists were initially out of luck, however: A full moon meant the telescope was not able to operate during the time in question.

Gravitational lens deflects ultra-high-energy photons

Eleven days later, MAGIC got a second chance, as the gamma rays emitted by QSO B0218+357 did not take the direct route to Earth: One billion years after setting off on their journey, they reached the galaxy B0218+357G. This is where Einstein’s General Theory of Relativity came into play.

This states that a large mass in the universe, a galaxy, for example, deflects light of an object behind it. In addition, the light is focused as if by a gigantic optical lens — to a distant observer, the object appears to be much brighter, but also distorted. The light beams also need different lengths of time to pass through the lens, depending on the angle of observation.

This gravitational lens was the reason that MAGIC was able, after all, to measure QSO B0218+357 — and thus the most distant object in the high-energy gamma ray spectrum. “We knew from observations undertaken by the Fermi space telescope and radio telescopes in 2012 that the photons that took the longer route would arrive 11 days later,” says Julian Sitarek (University of ?ódz, Poland), who led this study. “This was the first time we were able to observe that high-energy photons were deflected by a gravitational lens.”

Doubling the size of the gamma-ray universe

The fact that gamma rays of such high energy from a distant celestial body reach Earth’s atmosphere is anything but obvious. “Many gamma rays are lost when they interact with photons which originate from galaxies or stars and have a lower energy,” says Mirzoyan. “With the MAGIC observation, the part of the universe that we can observe via gamma rays has doubled.”

The fact that the light arrived on Earth at the time calculated could rattle a few theories on the structure of the vacuum — further investigations, however, are required to confirm this. “The observation currently points to new possibilities for high-energy gamma ray observatories — and provides a pointer for the next generation of telescopes in the CTA project,” says Mirzoyan, summing up the situation.

Tsunami Of Stars And Gas Produces Dazzling Eye-Shaped Feature In Galaxy

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered a tsunami of stars and gas that is crashing midway through the disk of a spiral galaxy known as IC 2163. This colossal wave of material — which was triggered when IC 2163 recently sideswiped another spiral galaxy dubbed NGC 2207 — produced dazzling arcs of intense star formation that resemble a pair of eyelids.

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“Although galaxy collisions of this type are not uncommon, only a few galaxies with eye-like, or ocular, structures are known to exist,” said Michele Kaufman, an astronomer formerly with The Ohio State University in Columbus and lead author on a paper published in the Astrophysical Journal.

Kaufman and her colleagues note that the paucity of similar features in the observable universe is likely due to their ephemeral nature. “Galactic eyelids last only a few tens of millions of years, which is incredibly brief in the lifespan of a galaxy. Finding one in such a newly formed state gives us an exceptional opportunity to study what happens when one galaxy grazes another,” said Kaufman.

The interacting pair of galaxies resides approximately 114 million light-years from Earth in the direction of the constellation Canis Major. These galaxies brushed past each other — scraping the edges of their outer spiral arms — in what is likely the first encounter of an eventual merger.

Using ALMA’s remarkable sensitivity and resolution, the astronomers made the most detailed measurements ever of the motion of carbon monoxide gas in the galaxy’s narrow eyelid features. Carbon monoxide is a tracer of molecular gas, which is the fuel for star formation.

The data reveal that the gas in the outer portion of IC 2163’s eyelids is racing inward at speeds in excess of 100 kilometers a second. This gas, however, quickly decelerates and its motion becomes more chaotic, eventually changing trajectory and aligning itself with the rotation of the galaxy rather than continuing its pell-mell rush toward the center.

“What we observe in this galaxy is very much like a massive ocean wave barreling toward shore until it interacts with the shallows, causing it to lose momentum and dump all of its water and sand on the beach,” said Bruce Elmegreen, a scientist with IBM’s T.J. Watson Research Center in Yorktown Heights, New York, and co-author on the paper.

“Not only do we find a rapid deceleration of the gas as it moves from the outer to the inner edge of the eyelids, but we also measure that the more rapidly it decelerates, the denser the molecular gas becomes,” said Kaufman. “This direct measurement of compression shows how the encounter between the two galaxies drives gas to pile up, spawn new star clusters and form these dazzling eyelid features.”

Computer models predict that such eyelid-like features could evolve if galaxies interacted in a very specific manner. “This evidence for a strong shock in the eyelids is terrific. It’s all very well to have a theory and simulations suggesting it should be true, but real observational evidence is great,” said Curtis Struck, a professor of astrophysics at Iowa State University in Ames and co-author on the paper.

“ALMA showed us that the velocities of the molecular gas in the eyelids are on the right track with the predictions we get from computer models,” said Kaufman. “This critical test of encounter simulations was not possible before.”

Astronomers believe that such collisions between galaxies were common in the early universe when galaxies were closer together. At that time, however, galactic disks were generally clumpy and irregular, so other processes likely overwhelmed the formation of similar eyelid features.

The authors continue to study this galaxy pair and currently are comparing the properties (e.g., locations, ages, and masses) of the star clusters previously observed with NASA’s Hubble Space Telescope with the properties of the molecular clouds observed with ALMA. They hope to better understand the differences between molecular clouds and star clusters in the eyelids and those elsewhere in the galaxy pair.

Significant Bronze Age city discovered in Northern Iraq

Archeologists from the Institute for Ancient Near Eastern Studies (IANES) at the University of Tübingen have uncovered a large Bronze Age city not far from the town of Dohuk in northern Iraq. The excavation work has demonstrated that the settlement, which is now home to the small Kurdish village of Bassetki in the Autonomous Region of Kurdistan, was established in about 3000 BC and was able to flourish for more than 1200 years. The archeologists also discovered settlement layers dating from the Akkadian Empire period (2340-2200 BC), which is regarded as the first world empire in human history.

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Scientists headed by Professor Peter Pfälzner from the University of Tübingen and Dr. Hasan Qasim from the Directorate of Antiquities in Dohuk conducted the excavation work in Bassetki between August and October 2016. As a result, they were able to preempt the construction work on a highway on this land. The former significance of the settlement can be seen from the finds discovered during the excavation work. The city already had a wall running around the upper part of the town from approx. 2700 BC onwards in order to protect its residents from invaders. Large stone structures were erected there in about 1800 BC. The researchers also found fragments of Assyrian cuneiform tablets dating from about 1300 BC, which suggested the existence of a temple dedicated to the Mesopotamian weather god Adad on this site. There was a lower town about one kilometer long outside the city center. Using geomagnetic resistance measurements, the archeologists discovered indications of an extensive road network, various residential districts, grand houses and a kind of palatial building dating from the Bronze Age. The residents buried their dead at a cemetery outside the city. The settlement was connected to the neighboring regions of Mesopotamia and Anatolia via an overland roadway dating from about 1800 BC.

Bassetki was only known to the general public in the past because of the “Bassetki statue,” which was discovered there by chance in 1975. This is a fragment of a bronze figure of the Akkadian god-king Naram-Sin (about 2250 BC). The discovery was stolen from the National Museum in Baghdad during the Iraq War in 2003, but was later rediscovered by US soldiers. Up until now, researchers were unable to explain the location of the find. The archeologists have now been able to substantiate their assumption that an important outpost of Akkadian culture may have been located there.

Although the excavation site is only 45 kilometers from territory controlled by the Islamic State (IS), it was possible to conduct the archeological work without any disturbances. “The protection of our employees is always our top priority. Despite the geographical proximity to IS, there’s a great deal of security and stability in the Kurdish autonomous areas in Iraq,” said Professor Peter Pfälzner, Director of the Department of Near Eastern Archaeology at the IANES of the University of Tübingen. The research team consisting of 30 people lived in the city of Dohuk, which is only 60 kilometers north of Mosul, during the excavation work.

In another project being handled by the “ResourceCultures” collaborative research center (SFB 1070), Pfälzner’s team has been completing an archeological inspection of territory in the complete area surrounding Bassetki as far as the Turkish and Syrian borders since 2013 — and 300 previously unknown sites have been discovered. The excavations and the research work in the region are due to be continued during the summer of 2017. “The area around Bassetki is proving to be an unexpectedly rich cultural region, which was located at the crossroads of communication ways between the Mesopotamian, Syrian and Anatolian cultures during the Bronze Age. We’re therefore planning to establish a long-term archeological research project in the region in conjunction with our Kurdish colleagues,” says Pfälzner. The excavation work is being funded by the Fritz Thyssen Foundation.

Pillars Of Cosmic Destruction: Colorful Carina Nebula Blasted By Brilliant Nearby Stars

Spectacular new observations of vast pillar-like structures within the Carina Nebula have been made using the M– USE instrument on ESO’s Very Large Telescope. The different pillars analysed by an international team seem to be pillars of destruction — in contrast to the name of the iconic Pillars of Creation in the Eagle Nebula, which are of similar nature.The spires and pillars in the new images of the Carina Nebula are vast clouds of dust and gas within a hub of star formation about 7500 light-years away. The pillars in the nebula were observed by a team led by Anna McLeod, a PhD student at ESO, using the M– USE instrument on ESO’s Very Large Telescope.

pillars

The great power of M– USE is that it creates thousands of images of the nebula at the same time, each at a different wavelength of light. This allows astronomers to map out the chemical and physical properties of the material at different points in the nebula.

Images of similar structures, the famous Pillars of Creation* in the Eagle Nebula and formations in NGC 3603, were combined with the ones displayed here. In total ten pillars have been observed, and in so doing a clear link was observed between the radiation emitted by nearby massive stars and the features of the pillars themselves.

In an ironic twist, one of the first consequences of the formation of a massive star is that it starts to destroy the cloud from which it was born. The idea that massive stars will have a considerable effect on their surroundings is not new: such stars are known to blast out vast quantities of powerful, ionising radiation — emission with enough energy to strip atoms of their orbiting electrons. However, it is very difficult to obtain observational evidence of the interplay between such stars and their surroundings.

The team analysed the effect of this energetic radiation on the pillars: a process known as photoevaporation, when gas is ionised and then disperses away. By observing the results of photoevaporation — which included the loss of mass from the pillars — they were able to deduce the culprits. There was a clear correlation between the amount of ionising radiation being emitted by nearby stars, and the dissipation of the pillars.

This might seem like a cosmic calamity, with massive stars turning on their own creators. However the complexities of the feedback mechanisms between the stars and the pillars are poorly understood. These pillars might look dense, but the clouds of dust and gas which make up nebulae are actually very diffuse. It is possible that the radiation and stellar winds from massive stars actually help create denser spots within the pillars, which can then form stars.

These breathtaking celestial structures have more to tell us, and M– USE is an ideal instrument to probe them with.

Psychology Researchers Map Neurological Process Of Learning, Deciding

Scientists at The University of Texas at Austin can now map what happens neurologically when new information influences a person to change his or her mind, a finding that offers more insight into the mechanics of learning.

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The study, which was published Nov. 1 in the Proceedings of the National Academy of Sciences, examined how dynamic shifts in a person’s knowledge are updated in the brain and impact decision making.

“At a fundamental level, it is difficult to measure what someone knows,” said co-author and psychology associate professor Alison Preston. “In our new paper, we employ brain decoding techniques that allow us deeper insight into the knowledge people have available to make decisions. We were able to measure when a person’s knowledge changes to reflect new goals or opinions.”

The process, researchers said, involves two components of the brain working together to update and “bias” conceptual knowledge with new information to form new ideas.

“How we reconcile that new information with our prior knowledge is the essence of learning. And, understanding how that process happens in the brain is the key to solving the puzzle of why learning sometimes fails and how to put learning back on track,” said the study’s lead author Michael Mack, who was a postdoctoral researcher in the Center for Learning & Memory.

In the study, researchers monitored neural activity while participants learned to classify a group of images in two different ways. First participants had to learn how to conceptualize the group of images, or determine how the images were similar to each other based on similar features. Once they grouped the images, participants were then asked to switch their attention to other features within the images and group them based on these similarities instead.

“By holding the stimuli constant and varying which features should be attended to across tasks, the features that were once relevant become irrelevant, and the items that were once conceptually similar may become very different,” said Preston, who holds a joint faculty appointment in neuroscience.

For example, the researchers report that many Americans may have chosen their preferred presidential candidate many months ago based on political platforms or core issues. But as the election cycle continued, voters were presented with new information, influencing some to change their perspectives on the candidates and, potentially, their votes.

This requires rapid updating of conceptual representations, a process that occurs in the hippocampi (HPC) — two seahorse-shaped areas near the center of the brain responsible for recording experiences, or episodic memory — researchers said. It’s also one of the first areas to suffer damage in Alzheimer’s disease.

According to the study, the prefrontal cortex (PFC) — the front part of the brain that orchestrates thoughts and actions — tunes selective attention to relevant features and compares that information with the existing conceptual knowledge in the HPC, updating the organization of items based on the new relevant features, researchers said.

“Looking forward, our findings place HPC as a central component of cognition — it is the brain’s code builder. I think these findings will motivate future research to consider the more general-purpose function of the hippocampus,” said Mack, who is now an assistant professor of psychology at the University of Toronto. “For example, understanding how we dynamically update conceptual knowledge may be essential to understanding how biases and prejudices are coded into our views of other people.”

These findings add to the growing, though limited, body of literature on the function of the HPC beyond episodic memory by providing direct evidence of its role, in concert with the PFC, in building conceptual knowledge.

“With an understanding of the mechanics of learning, we can develop educational practices and training protocols that optimally engage the brain’s learning circuits to build lasting knowledge,” Mack said.

Close Galactic Encounter Leaves ‘Nearly Naked’ Supermassive Black Hole

Astronomers using the super-sharp radio vision of the National Science Foundation’s Very Long Baseline Array (VLBA) have found the shredded remains of a galaxy that passed through a larger galaxy, leaving only the smaller galaxy’s nearly-naked supermassive black hole to emerge and speed away at more than 2,000 miles per second.

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The galaxies are part of a cluster of galaxies more than 2 billion light-years from Earth. The close encounter, millions of years ago, stripped the smaller galaxy of nearly all its stars and gas. What remains is its black hole and a small galactic remnant only about 3,000 light-years across. For comparison, our Milky Way Galaxy is approximately 100,000 light-years across.

The discovery was made as part of a program to detect supermassive black holes, millions or billions of times more massive than the Sun, that are not at the centers of galaxies. Supermassive black holes reside at the centers of most galaxies. Large galaxies are thought to grow by devouring smaller companions. In such cases, the black holes of both are expected to orbit each other, eventually merging.

“We were looking for orbiting pairs of supermassive black holes, with one offset from the center of a galaxy, as telltale evidence of a previous galaxy merger,” said James Condon, of the National Radio Astronomy Observatory. “Instead, we found this black hole fleeing from the larger galaxy and leaving a trail of debris behind it,” he added.

“We’ve not seen anything like this before,” Condon said.

The astronomers began their quest by using the VLBA to make very high resolution images of more than 1,200 galaxies, previously identified by large-scale sky surveys done with infrared and radio telescopes. Their VLBA observations showed that the supermassive black holes of nearly all these galaxies were at the centers of the galaxies.

However, one object, in a cluster of galaxies called ZwCl 8193, did not fit that pattern. Further studies showed that this object, called B3 1715+425, is a supermassive black hole surrounded by a galaxy much smaller and fainter than would be expected. In addition, this object is speeding away from the core of a much larger galaxy, leaving a wake of ionized gas behind it.

The scientists concluded that B3 1715+425 is what has remained of a galaxy that passed through the larger galaxy and had most of its stars and gas stripped away by the encounter — a “nearly naked” supermassive black hole.

The speeding remnant, the scientists said, probably will lose more mass and cease forming new stars.

“In a billion years or so, it probably will be invisible,” Condon said. That means, he pointed out, that there could be many more such objects left over from earlier galactic encounters that astronomers can’t detect.

The scientists will keep looking, however. They’re observing more objects, in a long-term project with the VLBA. Since their project is not time-critical, Condon explained, they use “filler time” when the telescope is not in use for other observations.

“The data we get from the VLBA is very high quality. We get the positions of the supermassive black holes to extremely good precision. Our limiting factor is the precision of the galaxy positions seen at other wavelengths that we use for comparison,” Condon said. With new optical telescopes that will come on line in future years, such as the Large Synoptic Survey Telescope (LSST), he said, they will then have improved images that can be compared with the VLBA images. They hope that this will allow them to discover more objects like B3 1714+425.

“And also maybe some of the binary supermassive black holes we originally sought,” he said.