CXC: X-Ray View of A Thousand-Year-Old Cosmic Tapestry

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CXC: X-Ray View of A Thousand-Year-Old Cosmic Tapestry

Post by bystander » Sun Apr 21, 2013 6:39 am

SN 1006: X-Ray View of A Thousand-Year-Old Cosmic Tapestry
NASA | Marshall | SAO | Chandra X-ray Observatory | 2013 Apr 17
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This year, astronomers around the world have been celebrating the 50th anniversary of X-ray astronomy. Few objects better illustrate the progress of the field in the past half-century than the supernova remnant known as SN 1006.

When the object we now call SN 1006 first appeared on May 1, 1006 A.D., it was far brighter than Venus and visible during the daytime for weeks. Astronomers in China, Japan, Europe, and the Arab world all documented this spectacular sight. With the advent of the Space Age in the 1960s, scientists were able to launch instruments and detectors above Earth's atmosphere to observe the Universe in wavelengths that are blocked from the ground, including X-rays. SN 1006 was one of the faintest X-ray sources detected by the first generation of X-ray satellites.

A new image of SN 1006 from NASA's Chandra X-ray Observatory reveals this supernova remnant in exquisite detail. By overlapping ten different pointings of Chandra's field-of-view, astronomers have stitched together a cosmic tapestry of the debris field that was created when a white dwarf star exploded, sending its material hurtling into space. In this new Chandra image, low, medium, and higher-energy X-rays are colored red, green, and blue respectively.

The Chandra image provides new insight into the nature of SN1006, which is the remnant of a so-called Type Ia supernova . This class of supernova is caused when a white dwarf pulls too much mass from a companion star and explodes, or when two white dwarfs merge and explode. Understanding Type Ia supernovas is especially important because astronomers use observations of these explosions in distant galaxies as mileposts to mark the expansion of the Universe.

The new SN 1006 image represents the most spatially detailed map yet of the material ejected during a Type Ia supernova. By examining the different elements in the debris field -- such as silicon, oxygen, and magnesium -- the researchers may be able to piece together how the star looked before it exploded and the order that the layers of the star were ejected, and constrain theoretical models for the explosion.

Scientists are also able to study just how fast specific knots of material are moving away from the original explosion. The fastest knots are moving outward at almost eleven million miles per hour, while those in other areas are moving at a more leisurely seven million miles per hour. SN 1006 is located about 7,000 light years from Earth. The new Chandra image of SN 1006 contains over 8 days worth of observing time by the telescope. These results were presented at a meeting of High Energy Astrophysics Division of the American Astronomical Society in Monterey, CA.

Image Credit: NASA/CXC/Middlebury College/F.Winkler

X-ray Proper Motions and Shock Speeds along the Northwest Rim of SN 1006 - Satoru Katsuda et al
http://asterisk.apod.com/viewtopic.php? ... 53#p197453
http://asterisk.apod.com/viewtopic.php? ... 20#p197520
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SAO: Supernovae and the Origin of Cosmic Rays

Post by bystander » Sun Apr 21, 2013 9:14 pm

Supernovae and the Origin of Cosmic Rays
Smithsonian Astrophysical Observatory
Weekly Science Update | 2013 Apr 19
In the spring of the year 1006, one thousand and seven years ago this April, observers in China, Egypt, Iraq, Japan, Switzerland (and perhaps North America) reported seeing what might be the brightest stellar event in recorded history: a supernova ("SN1006") that was relatively close to Earth, only about seven thousand light-years away. It was reportedly so bright that it cast shadows at night. In 1965, radio astronomers identified the residue of this event, a so-called supernovae remnant, in the form of a sixty light-year diameter shell of glowing gas. Current models of the cataclysm find that it resulted when two white dwarf stars (each being a late stage of a star’s life) merged together.

Supernovae are critical to life in the universe. They and their progenitor stars create most of the elements in the universe, and their explosive deaths disburse them into interstellar space where they can later be incorporated into new stars and planets. Supernovae are also active research topics because their bright emission enables them to be used as probes of the very distant universe. Not least, supernovae are astrophysical laboratories for the study of very high-velocity shocks and the physics of particles under extreme conditions.

CfA astronomer John Raymond and seven colleagues, writing in the latest issue of Science magazine, investigate the links between supernova remnants and cosmic rays - the very rapidly moving nuclear particles that impact the earth from space. Cosmic rays can have energies millions of times larger than the most energetic particles produced in man-made particle accelerators, but astronomers are not sure where they come from or how they are accelerated to such fantastic energies. Supernovae have been a likely suspect for over fifty years because their powerful shocks were thought to be capable of accelerating subatomic particles to high energies. In their new paper, the scientists used a new optical spectrometer to analyze in detail the shock activity at the outer edge of SN1006. They report finding gas motions of over five thousand kilometers per second and evidence for the presence of fast-moving protons (as well as for fast moving but much less massive electrons). The team suggests that such protons may be the seed particles for cosmic rays once they are further accelerated by the shocks. The study with its new techniques offer powerful new evidence towards clarifying the role of supernova remnants in the production of the mystery cosmic rays.

An Integral View of Fast Shocks around Supernova 1006 - Sladjana Nikolić et al
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Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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