Mercury,
March/April 2001 Table of Contents
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Images
Courtesy of NASA/SAO/CXC/Giuseppina Fabbiano et al. and NASA/CXC/SAO. |
Chandras
first 18 months in orbit have yielded a bonanza of scientific discoveries.
by
Christopher Wanjek
If
you zoom past the Virgo cluster and continue toward the north celestial
pole for several billion light-years, you will come across a collection
of odd galaxies that seems to shine only in X rays. Are these galaxies
so far away that their visible light didnt make it through
the long, dusty voyage across the universe? Or are these actually
protogalaxies, so young that they comprise only a central supermassive
black hole and a swirl of hot X-ray-emitting gas in an era before
starlight?
The
verdict is still out. But whatever these objects are, we werent
able to see them at all with any instrument before the launch of
NASAs Chandra X-ray Observatory in July 1999.
With
an imaging capability at least 30 times sharper than any X-ray telescope
before it, and four of the smoothest, cleanest mirrors ever made,
Chandra is the 190-proof intoxicant putting hair on the chest of
X-ray astronomy. Scientists at long last have a superior tool to
study the structure and dynamics of the most energetic and enigmatic
phenomena in the universe, such as black holes, supernovae, and
neutron stars.
Chandra
is the X-ray astronomers version of the Hubble Space Telescope,
designed to provide detail of objects and events that have remained
shaded in mystery for decades. One of Chandras first images,
in fact, revealed what may be the long sought neutron star in the
heart of the Cassiopeia A supernova remnant, some 11,000 light-years
away. Radio, optical, and earlier X-ray telescopes had searched
for this source to no avail.
NASA
promised that the Chandra mission would be tantamount to finally
seeing the universe through a good pair of X-ray eyeglasses. Chandras
first year has proven this analogy lame. Toss the eyeglasses; Chandra
grabs you by the arm and takes you to the scene of the crime.
This
feature article also contains a sidebar about the European Space
Agencys answer to Chandra: The XMM-Newton mission. Another
sidebar talks about astronomer Harvey Tananbaum, one of the key
players who developed Chandra.
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