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A
Textbook Supernova
01/30/07
G11.2-0.3
is a circularly symmetric supernova remnant
Credit:
NASA/CXC/Eureka
Scientific/M.Roberts et al.
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G11.2-0.3
is a circularly symmetric supernova remnant that contains a
dense, rotating dead star at its center, representing a textbook
case of what the remnant of an exploding star should look like
after a couple thousand years. When a massive star collapses, the
outer layers of the star are blown away in an extremely energetic
explosion. Depending on the mass of the original star, a dense
object such as a neutron star or a black hole, can form and be
left behind at the explosion's center. Such a neutron star, known
as a "pulsar" when it rapidly rotates, can be kicked by
the thermonuclear shock wave created when the star exploded,
causing it to race through space at millions of miles per hour.
Chandra
X-ray & VLA Radio Images of G11.2-0.3
Each
image contains a HOT SPOT to a Hi-Res Version
More
Information ROLLOVER
Credit:
NASA/CXC/Eureka Scientific/M.Roberts et al.
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By combining X-ray and
radio observations, astronomers have evidence that G11.2-0.3 is
likely the result of the explosive death of such a massive star,
perhaps witnessed in 386 A.D. Radio observations measure the
remnant's expansion rate, which, in turn, can be used to
calculate how long ago the star exploded. The radio data is
consistent with association of the supernova remnant with the
"guest star" reported by Chinese astronomers nearly
2,000 years ago. Chandra's ability to pinpoint the pulsar at
nearly the very center of G11.2-0.3 also supports the idea that
this debris field could have been created around the time of the
Chinese observations. Surprisingly, the age of the pulsar
determined from the X-ray and radio data differs from the
standard pulsar age estimate, usually determined from how fast it
is spinning. In this case, the so-called spin parameters suggest
the G11.2-0.3 is 10 times older than the remnant age. This argues
strongly that young pulsar spin ages can be very misleading and
should be considered with caution.
In Chandra's X-ray
image, the pulsar and a cigar-shaped cloud of energetic
particles, known as a pulsar wind nebula, are predominantly seen
as high-energy X-rays (blue). A shell of heated gas from the
outer layers of the exploded star surrounds the pulsar and the
pulsar wind nebular and emits lower-energy X-rays (represented in
green and red).
Source
/ Credit: NASA / Chandra X-Ray
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