Credit: NASA/ROSAT/GSFC and NASA/CXC/SAO
X-ray Emission from the Crab Nebula
The Crab
Nebula is a large cloud of gas which was produced a stellar explosion
that was seen in AD 1054. The nebula is 6000 light years from Earth, so the
explosion observed in AD 1054 actually occurred 6000 years earlier. Stars
with masses of more than 10 times the sun's mass are thought to end their
lives in great cataclysmic explosions called supernovae. When a
supernova occurs, most of the material which comprises the star gets thrown
out into space. The small core of the star (typically a sphere of about 10
km in radius) may remain behind as an ultradense "compact object", generally a
neutron star, but sometimes, in extreme cases, a black hole. In the case
of the Crab Nebula, we can see both the nebula and the neutron star. The
neutron star spins very rapidly, about 30 times per second.
X-ray emission from the Crab Nebula allows us to probe the ejected outer
material, along with the regions nearest the neutron star. The images
above show 3 views of the crab nebula; the image on the left was obtained
by the high resolution imager on the ROSAT X-ray observatory, while the
middle image is the ROSAT HRI
image represented as a 3-D surface. These images show the bright
point-like emission associated with the neutron star, along with emission
from material farther out. The recent Chandra X-ray
observatory image represents the best view of the X-ray emission from
the Crab ever obtained. The Chandra image shows tilted rings or waves of
high-energy particles that appear to have been flung outward over the
distance of a light year from the central star, and high-energy jets of
particles blasting away from the neutron star in a direction perpendicular
to the spiral.
Last Week *
HEA Dictionary * Archive
* Search HEAPOW
* Education
Each week the HEASARC
brings you new, exciting and beautiful images from X-ray and Gamma ray
astronomy. Check back each week and be sure to check out the HEAPOW archive!
Page Author: Dr. Michael F.
Corcoran
Last modified May 26, 2001
