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G292.0+1.8:
Chandra Looks at the Aftermath of a Massive Star Explosion
NASA's Chandra X-ray Observatory
has captured a spectacular image of G292.0+1.8, a
young, oxygen-rich supernova remnant with a pulsar at
its center surrounded by outflowing material.
Astronomers know that pulsars are formed in supernova
explosions, but they are currently unable to identify
what types of massive stars must die in order for a
pulsar to be born. Now that Chandra has revealed strong
evidence for a pulsar in G292.0+1.8, astronomers can
use the pattern of elements seen in the remnant to make
a much closer connection between pulsars and the
massive stars from which they form.
This Chandra image shows a rapidly expanding shell of
gas that is 36 light years across and contains large
amounts of elements such as oxygen, neon, magnesium,
silicon and sulfur. Embedded in this cloud of
multimillion degree gas is a key piece of evidence
linking neutron stars and supernovas produced by the
collapse of massive stars.
Standing out at higher X-ray energies, astronomers
found a point-like source surrounded by features
strikingly similar to those found around the Crab Nebula and Vela pulsars.
These features, together with the X-ray spectrum of the
central source and surrounding nebula, provide strong
evidence that a rapidly spinning neutron star is
responsible for the central observed X-radiation.
Astronomers believe that an oxygen-rich supernova
explosion is triggered by the collapse of the core of a
massive star to form a neutron star, releasing
tremendous amounts of energy in the process. "This finding is very important, since it would allow us to conclusively associate this young, oxygen-rich supernova remnant with a core collapse, massive star supernova explosion," said John P. Hughes of Rutgers
University, lead author of a paper describing the
research which appeared in the October 1, 2001, issue
of The Astrophysical Journal.
With an age estimated at 1,600 years, G292.0+1.8 is
one of three known oxygen-rich supernovas in our
Galaxy. These supernovas are of great interest to
astronomers because they are one of the primary sources
of the heavy elements necessary to form planets and
people.
Scattered throughout the image are bluish knots of
emission containing material that is highly enriched in
oxygen, neon, and magnesium produced deep within the
original star and ejected by the supernova explosion.
Elsewhere in the image one can trace whitish colored
regions (like the thin, nearly horizontal filaments
just above the purple nebula) and yellow regions
(scattered internally, and around the periphery). This
material is of a more standard composition without the
enrichment seen elsewhere and represents either the
pre-existing surrounding matter or the outer layers of
the star itself, lost at an earlier time before the
star exploded as a supernova.
The research team, which also included Patrick Slane
(Smithsonian Astrophysical Observatory), David Burrows,
Gordon Garmire, and John Nousek (Penn State
University), Charles Olbert and Jonathan Keohane (North
Carolina School of Science and Mathematics), used the
Advanced CCD Imaging Spectrometer instrument to observe
G292.0+1.8 on March 11, 2000.
NOTE: The Chandra results prompted a team of
radio astronomers led by Fernando Camilo of Columbia
University to use the Parkes radio telescope in
Australia to observe the pointlike X-ray source in
G292.0+1.8. On October 3, 2001 they discovered that it
is a radio pulsar with a period of 135
milliseconds.
| Fast Facts for G292.0+1.8: |
| Credit |
NASA/CXC/Rutgers/J.Hughes et al. |
| Scale |
Image is 9 arcmin per side. |
| Category |
Supernovas & Supernova Remnants |
| Coordinates (J2000) |
RA 11h 24m 36.00s | Dec -59° 16' 00.00" |
| Constellation |
Centaurus |
| Observation Dates |
March 11, 2000
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| Observation Time |
12 hours |
| Obs. IDs |
126
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| Color Code |
Intensity |
| Instrument |
ACIS |
| References | J.P. Hughes et al. 2001, Astrophys.J. 559, L153 |
| Distance Estimate |
About 20,000 light years |
| Release Date |
October 22, 2001 |
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