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CHANDRA LOOKS AT THE AFTERMATH OF A MASSIVE STAR EXPLOSION
22-October-2001
Article courtesy of Chandra X-ray Observatory Center
Image credit: NASA/CXC/Rutgers/J. Hughes et al.
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 supernovae 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 supernovae in our Galaxy. These supernovae 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 newly created 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 (mainly around the periphery, best
seen toward the upper right). 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.
ACIS was conceived and developed for NASA by Penn State and MIT
under Garmire's leadership. NASA's Marshall Space Flight
Center in Huntsville, Alabama, manages the Chandra program. TRW, Inc.,
in Redondo Beach, California, is the prime contractor for the
spacecraft. The Smithsonian's Chandra X-ray Center controls science and
flight operations from Cambridge, Massachusetts.
The images of G292.0+1.8, as well as additional information, are
available at:
http://chandra.harvard.edu
http://chandra.nasa.gov
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