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X-ray Laser Takes Aim At Cosmic Mystery

December 12, 2012 Leave a comment

Scientists have used powerful X-rays from the Linac Coherent Light Source (LCLS) at the U.S. Department of Energy’s (DOE) SLAC National Accelerator Laboratory to study and measure, in atomic detail, a key process at work in extreme plasmas like those found in stars, the rims of black holes and other massive cosmic phenomena.

The results explain why observations from orbiting X-ray telescopes do not match theoretical predictions, and pave the way for future X-ray astrophysics research using free-electron lasers such as LCLS. With its brilliant, ultrafast X-ray laser pulses, LCLS allows scientists to create and measure atomic processes in extreme plasmas in a fully controlled way for the first time.

“Measurements conducted at the LCLS will be important for interpreting X-ray emissions from a plethora of sources, including black holes, X-ray binaries, stellar coronae and supernova remnants, to name a few,” said Gregory V. Brown, a physicist at Lawrence Livermore National Laboratory who participated in the research.

Full Story: http://www6.slac.stanford.edu/news/2012-12-12-cosmic-lcls.aspx
Also: https://www.llnl.gov/news/newsreleases/2012/Dec/NR-12-12-01.html

Hubble Census Finds Galaxies At Redshifts 9 To 12

December 12, 2012 Leave a comment

Credit: NASA, ESA, R. Ellis (Caltech), and the UDF 2012 Team

Credit: NASA, ESA, R. Ellis (Caltech), and the UDF 2012 Team

Astronomers using the NASA/ESA Hubble Space Telescope have uncovered seven primitive galaxies from a distant population that formed more than 13 billion years ago. In the process, their observations have put forward a candidate for the record for the most distant galaxy found to date (at redshift 11.9), and have shed new light on the earliest years of cosmic history. The galaxies are seen as they were when the Universe was less than 4 percent of its present age.

The new data have allowed the team, co-led by Richard Ellis (Caltech, USA) and Ross McLure (University of Edinburgh, UK), to uncover six previously-unknown galaxies in this era, and to rule out a number of tentative identifications of distant galaxies made by other scientists in previous research. This is the first statistically robust census of galaxies at such an early time in cosmic history, and shows that the number of galaxies steadily increased with time, supporting the idea that the first galaxies didn’t form in a sudden burst but gradually assembled their stars.

“Our study has taken the subject forward in two ways,” says Ellis. “First, we have used Hubble to make longer exposures than previously. The added depth is essential to reliably probe the early period of cosmic history. Second, we have used Hubble’s available colour filters very effectively to measure galaxy distances more precisely.”

Full Story: http://www.spacetelescope.org/news/heic1219/
Also: http://hubblesite.org/newscenter/archive/releases/2012/48/full/
Also: http://www.caltech.edu/content/caltech-led-astronomers-discover-galaxies-near-cosmic-dawn

Cassini Spots Mini Nile River on Saturn Moon

December 12, 2012 Leave a comment

Image Credit: NASA/JPL-Caltech/ASI

Image Credit: NASA/JPL-Caltech/ASI

The international Cassini mission has spotted what appears to be a miniature extraterrestrial version of the Nile River: a river valley on Saturn’s moon Titan that stretches more than 400 km from its ‘headwaters’ to a large sea. It is the first time images have revealed a river system this vast and in such high resolution anywhere beyond Earth.

Scientists deduce that the river is filled with liquid because it appears dark along its entire extent in the high-resolution radar image, indicating a smooth surface.

“Though there are some short, local meanders, the relative straightness of the river valley suggests it follows the trace of at least one fault, similar to other large rivers running into the southern margin of this same Titan sea,” says Jani Radebaugh, a Cassini radar team associate at Brigham Young University, USA. “Such faults – fractures in Titan’s bedrock – may not imply plate tectonics, like on Earth, but still lead to the opening of basins and perhaps to the formation of the giant seas themselves.”

Full Story: http://www.esa.int/Our_Activities/Space_Science/Cassini_spots_mini_Nile_River_on_Saturn_moon
Also: http://www.jpl.nasa.gov/news/news.php?release=2012-394

NASA Celebrates 50 Years Of Planetary Exploration

December 12, 2012 Leave a comment

Fifty years ago on a mid-December day, NASA’s Mariner 2 spacecraft sailed close to the shrouded planet Venus, marking the first time any spacecraft had ever successfully made a close-up study of another planet. The flyby, 36 million miles (58 million kilometers) away from Earth, gave America its first bona fide space “first” after five years in which the Soviet Union led with several space exploration milestones. Designed and built by NASA’s Jet Propulsion Laboratory in Pasadena, Calif., the successful Mariner 2 spacecraft ushered in a new era of solar system exploration.

“JPL has always attempted to do mighty things on behalf of NASA and our nation,” said JPL director Charles Elachi. “Achieving America’s first ‘first in space’ is among the lab’s proudest achievements.”

In celebration of the anniversary, an interactive presentation highlighting 50 years of planetary exploration is available online.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2012-395
Online Presentation: http://www.jpl.nasa.gov/50years/

Microquasar Found In Neighbor Galaxy, Tantalizing Scientists

December 12, 2012 Leave a comment

For the first time, astronomers have found a microquasar — a black hole devouring material from a companion star — in a galaxy beyond our own Milky Way. The object, pumping out X-rays and bright bursts of radio waves, was found in the Andromeda Galaxy, 2.5 million light-years from Earth.

The discovery, scientists say, gives hope that more such objects may be found in nearby galaxies, providing them with opportunities to make detailed studies that will unravel the mystery of just how these enigmatic powerhouses — and their big brothers — actually work.

In a microquasar like the one newly discovered, a black hole with a mass several times that of the Sun pulls material from its companion star into a rapidly-rotating disk. The disk surrounding the black hole can become so hot it emits X-rays. The disk also propels narrow jets of subatomic particles outward at speeds nearing that of light. The jets generate strong bursts of radio emission.

Full Story: http://www.nrao.edu/pr/2012/microquasar/

KMOS Successfully Installed On ESO’s Very Large Telescope

December 12, 2012 Leave a comment

A powerful new instrument called KMOS has just been successfully tested on ESO’s Very Large Telescope at the Paranal Observatory in Chile. KMOS is unique as it will be able to observe not just one, but 24 objects at the same time in infrared light and study the structure simultaneously within each one. It will provide crucial data to help understand how galaxies grew and evolved in the early Universe — and provide it much faster than has been possible up to now. KMOS was built by a consortium of universities and institutes in the United Kingdom and Germany in collaboration with ESO.

The K-band Multi-Object Spectrograph (KMOS), attached to the Very Large Telescope (VLT) Unit Telescope 1 at ESO’s Paranal Observatory in Chile, has successfully achieved first light. During the four-month period from August this 2.5-tonne instrument had been shipped from Europe, reassembled, tested and installed following months of careful planning. This was the culmination of many years of design and construction by teams in the UK and Germany, and at ESO. KMOS is the second of the second generation of instruments to be installed on ESO’s VLT (The first was X-shooter.).

Full Story: http://www.eso.org/public/news/eso1251/

X-ray Vision Can Reveal The Moment Of Birth Of Violent Supernovae

December 12, 2012 Leave a comment

GRB 080913, a distant supernova detected by Swift. Credit: NASA/Swift/Stefan Immler

GRB 080913, a distant supernova detected by Swift. Credit: NASA/Swift/Stefan Immler

A team of astronomers led by the University of Leicester has uncovered new evidence that suggests that X-ray detectors in space could be the first to witness new supernovae that signal the death of massive stars. Astronomers have measured an excess of X-ray radiation in the first few minutes of collapsing massive stars, which may be the signature of the supernova shock wave first escaping from the star.

The findings have come as a surprise to Dr Rhaana Starling, of the University of Leicester Department of Physics and Astronomy, whose research is published in the Monthly Notices of the Royal Astronomical Society, published by Oxford University Press.

Dr Starling said: “The most massive stars can be tens to a hundred times larger than the Sun. When one of these giants runs out of hydrogen gas it collapses catastrophically and explodes as a supernova, blowing off its outer layers which enrich the Universe. But this is no ordinary supernova; in the explosion narrowly confined streams of material are forced out of the poles of the star at almost the speed of light. These so-called relativistic jets give rise to brief flashes of energetic gamma-radiation called gamma-ray bursts, which are picked up by monitoring instruments in Space, that in turn alert astronomers.”

Full Story: http://www.ras.org.uk/news-and-press/219-news-2012/2199-x-ray-vision-can-reveal-the-moment-of-birth-of-violent-supernovae
Also: http://www2.le.ac.uk/news/blog/2012/december/x-rays-could-provide-early-warning-of-supernovae