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Cassiopeia A:
Elemental Image Of Exploded Star
A new 14 hour Chandra observation
of the supernova remnant Cassiopeia A has given the
best map yet of heavy elements ejected in a supernova
explosion. Upper left: Broadband X-ray image of
Cassiopeia A (Cas A) Upper right: Image made by X rays
from silicon ions. Lower left: Image made by X rays
from calcium ions. Lower right: Image made by X rays
from iron ions. All images are 8.5 arc minutes on a
side (corresponding to 28.2 light years at a distance
of 11,000 light years).
These images are designed to show the distribution of
some of the elements ejected in the explosion that
produced Cas A. The elements are part of a gas that has
a temperature of about 50 million degrees Celsius. The
colors represent intensity of X rays, with yellow the
most intense, then red, purple, and green.
The broadband image, which shows all the X rays
detected from Cas A, is more symmetric than the others.
This could be due to the presence of X rays from
synchrotron radiation by extremely high-energy
particles spiraling in the magnetic field of the
remnant, or to shock waves traveling through material
puffed off thousands of years before the
supernova.
The silicon image shows a bright, broad jet breaking
out of the upper left side of the remnant, and faint
streamers in an opposite direction. This jet could be
due to an asymmetry in the explosion.
The calcium image is similar to the silicon image, but
less bright and clumpier. The iron image shows
significant differences from other images. Since iron
is the heaviest element shown, these maps support the
suggestion that the layers of the star were overturned
either before or during the explosion.
| Fast Facts for Cassiopeia A: |
| Credit |
NASA/GSFC/U.Hwang et al. |
| Scale |
All images are 8.5 arcmin on a side. |
| Category |
Supernovas & Supernova Remnants |
| Coordinates (J2000) |
RA 23h 23m 26.7s | Dec +58° 49' 03.00" |
| Constellation |
Cassiopeia |
| Observation Dates |
January 30 - 31, 2000
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| Observation Time |
14 hours |
| Obs. IDs |
114
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| Color Code |
Colors represent different energy bands |
| Instrument |
ACIS |
| Also Known As | Cas A |
| Distance Estimate |
About 10,000 light years |
| Release Date |
June 27, 2000 |
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Broadband
Silicon
Calcium
Iron
