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Archive for November, 2013

Neutrinos On Ice Now The Coolest New Astronomy Tool

November 21, 2013 Leave a comment

The IceCube Lab. Credit: Sven Lidstrom. IceCube/NSF

The IceCube Lab. Credit: Sven Lidstrom. IceCube/NSF

A massive telescope buried in the Antarctic ice has detected 28 record-breaking, extremely high-energy neutrinos — elementary particles that likely originate outside our solar system. The achievement, which comes nearly 25 years after the pioneering idea of detecting neutrinos in ice, provides the first solid evidence for astrophysical neutrinos from cosmic accelerators and has been hailed as the dawn of a new age of astronomy. The team researchers that detected the neutrinos with the new IceCube Neutrino Observatory in Antarctica, which includes Penn State scientists, will publish a paper describing the detections on 22 November 2013 in the journal Science.

“While it is premature to speculate about the precise origin of these neutrinos, their energies are too high to be produced by cosmic rays interacting in the Earth’s atmosphere, strongly suggesting that they are produced by distant accelerators of subatomic particles elsewhere in our galaxy, or even farther away,” said Penn State Associate Professor of Physics Tyce DeYoung, the deputy spokesperson of the IceCube Collaboration.

The neutrinos had energies greater than 1,000,000,000,000,000 electron volts or, as the scientists say, 1 peta-electron volt (PeV). Two of these neutrinos had energies many thousands of times higher than the highest-energy neutrino that any man-made particle accelerator has ever produced.

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Hubble Reveals First Scrapbook Pictures Of Milky Way’s Formative Years

November 21, 2013 Leave a comment

Artist's Illustration of the Early Milky Way. Credit: NASA, ESA, and Z. Levay (STScI/AURA)

Artist’s Illustration of the Early Milky Way. Credit: NASA, ESA, and Z. Levay (STScI/AURA)

According to new Hubble Space Telescope observations of our Milky Way’s siblings, which existed long ago, the night sky must have looked much emptier in the distant past, when our galaxy was still under construction. The vast majority of our Milky Way’s stars had not yet been born. Yet the heavens were ablaze with a firestorm of new star formation.

By tracing the Milky Way’s siblings, astronomers find that our galaxy built up most of its stars between 11 billion and 7 billion years ago. The Hubble telescope’s superb resolving power allowed the researchers to study how the structure of Milky Way-like galaxies changed over time. The observations suggest that our galaxy’s flat disk and central bulge grew simultaneously into the majestic spiral galaxy of today.

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New Data On The Composition Of Relativistic Jets From Black Holes

November 21, 2013 Leave a comment

Artist impression. Image: Riccardo Lanfranchi

Artist impression. Image: Riccardo Lanfranchi

It is known that black holes launch relativistic jets both in stellar-mass binary systems and at the centres of galaxies, in the so-called ‘quasars’. Although jets have been studied for decades, their composition has remained uncertain. Now, a work, published on Nature and led by researchers from the University of Barcelona, the German headquarters of the European Southern Observatory (ESO) and Curtin University (Australia), presents the detection of atomic nuclei in the relativistic jets from the black hole binary system 4U 1630-47.

“In this work, we have found the composition of relativistic jets launched from around black holes; however, more studies are needed to understand if results can be extrapolated to other relativistic jet sources”, explains Simone Migliari, from the Institute of Sciences of the Cosmos of the UB (ICCUB). According to the researcher, the research proves that relativistic jets might be ‘heavy jets’ containing atomic nuclei, rather than ‘light jets’ consisting of electrons and positrons only”. “The finding —he adds— implies that ‘heavy jets’ carry away significantly more energy from the black hole than ‘lighter’ ones”.

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Surprising Image Provides New Tool For Studying A Galaxy

November 15, 2013 Leave a comment

Credit: Jayanne English (U. of Manitoba), Judith Irwin (Queen's U.), Richard Rand (U. of New Mexico) and collaborators in the CHANG-ES consortium, NRAO VLA, NASA WISE & Spitzer missions, NOAO, and SDSS.

Credit: Jayanne English (U. of Manitoba), Judith Irwin (Queen’s U.), Richard Rand (U. of New Mexico) and collaborators in the CHANG-ES consortium, NRAO VLA, NASA WISE & Spitzer missions, NOAO, and SDSS.

Astronomers studying gas halos around nearby galaxies were surprised when detailed studies with the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) showed that one of their subjects is not a single galaxy, but rather two, nearly perfectly superimposed on the sky to masquerade as one. The discovery allowed them to use the alignment to learn otherwise-unobtainable facts about the nearer galaxy.

As part of a study of 35 galaxies, the astronomers observed one called UGC 10288, a spiral galaxy more than 100 million light-years distant that appears edge-on as seen from Earth. Their multiple VLA observations in 2011 and 2012 produced the best radio-telescope images of that galaxy ever made. The detailed images surprisingly revealed a more-distant galaxy, with strong radio emission, almost directly behind UGC 10288. In previous images, the two galaxies had been blended together.

The background galaxy is nearly 7 billion light-years from Earth.

“This changed the picture, quite literally,” said Judith Irwin, of Queen’s University in Ontario, Canada. “It changed our understanding of the characteristics of UGC 10288, but also gave us an unexpected new tool for learning more about that galaxy,” Irwin added. The alignment of a foreground galaxy with such a strongly-emitting background galaxy with extended jets probably is the first such alignment found, the astronomers said.

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Hubble Views An Old And Mysterious Cluster

November 15, 2013 Leave a comment

Image credit: NASA, ESA

Image credit: NASA, ESA

This multi-coloured firework display is a cluster of stars known as Messier 15, located some 35 000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters known, with an age of around 12 billion years.

Very hot blue stars and cooler golden stars are seen swarming together in this image, becoming more concentrated towards the cluster’s bright centre. Messier 15 is one of the densest globular clusters known, with most of its mass concentrated at its core.

However, this sparkling bauble has hidden secrets. Astronomers studying the cluster with Hubble in 2002 found there to be something dark and mysterious lurking at its heart. It could either be a collection of dark neutron stars, or an intermediate-mass black hole. Of the two possibilities it is more likely that Messier 15 harbours a black hole at its centre, as does the massive globular cluster Mayall II.

Intermediate-mass black holes are thought to form either from the merging of several smaller, stellar-mass black holes, or as a result of a collision between massive stars in dense clusters. A third possibility is that they were formed during the Big Bang. In terms of mass they lie between the more commonly found stellar-mass and supermassive types of black hole [3], and could tell us about how black holes grow and evolve within clusters like Messier 15, and within galaxies.

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MESSENGER Detects Comets ISON And Encke, Prepares For Closer Encounters

November 15, 2013 Leave a comment

NASA’s Mercury-orbiting MESSENGER spacecraft has captured images of two comets — 2P/Encke and C/2012 S1 (ISON) — setting the stage for observations later this month when both comets will be substantially brighter and much closer to Mercury and the Sun.

ISON was discovered in September 2012 by amateur Russian astronomers, who observed with a 16-inch telescope that is part of the International Scientific Optical Network (ISON), after which the comet was named. On November 28, ISON will fly within 700,000 miles (1.2 million kilometers) of the Sun’s photosphere, at which time it is expected either to flare brilliantly or disintegrate.

As part of an ISON observation campaign involving ground- and space-based NASA observatories, as well as many other observatories around the world, MESSENGER has been poised for several weeks to collect observations of ISON. From November 9 through November 11, the probe’s Mercury Dual Instrument System (MDIS) captured its first images of the comet.

A few days earlier, from November 6 through November 8, MESSENGER’s imagers picked up its first snapshots of Encke. Unlike ISON, Encke has been known for quite a while. It was discovered in 1786 and recognized as a periodic comet in 1819. Its orbital period is 3.3 years — the shortest period of any known comet — and November 21 will mark its 62nd recorded perihelion.

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Comet ISON On Track For Thanksgiving Roasting, Possible Pre-Dawn Views In Early December

November 15, 2013 Leave a comment

A comet that’s caused a lot of excitement is racing toward a close encounter with the Sun on Thanksgiving Day, according to the editors of StarDate magazine. Comet ISON will pass about 700,000 miles above the Sun before whipping around and heading back toward deep space — if it survives. If it does, the comet could easily be visible to the unaided eye for a few weeks after the encounter.

An automated asteroid-hunting telescope, part of the International Scientific Optical Network (ISON) in Russia, discovered Comet C/2012 S1 (ISON) on September 21, 2012. Some comet-watchers quickly suggested that it could become as bright as a full Moon late this year. Continued observations, however, show that it’s not brightening as much as those optimistic projections indicated.

However, the comet appears to be holding together as it approaches the Sun, suggesting that it could survive the solar encounter, probably its first.

The comet will get brighter as it approaches the Sun, but more difficult to see through the Sun’s glare. It will shine at its brightest as it passes the Sun, although it will be too close to the Sun to view safely.

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