Credit: Neil Brandt et al, PSU; ESA
The Oldest X-rays Ever
Quasi-stellar objects (QSOs) appear as unresolved stars when viewed through
even the most powerful telescopes. In reality QSOs are extremely distant,
extremely bright galaxies. QSOs appear to be moving away from us very
rapidly as a result of the expansion of the universe; the more distant the
QSO, the faster it moves away from us. Because QSOs are so distant, light
from QSOs can take billions of years to reach earth. Thus QSOs allow
astronomers to probe the conditions in the universe as it was billions of
years ago. QSOs are thought to be powered by supermassive black holes. By
studying X-ray emission from QSOs (and other active galaxies), astronomers
can probe the conditions very near the black hole. By studying QSOs at
different distances, astronomers can learn how the black holes evolve with
time. Recently X-ray emission from the most distant (and hence
youngest) QSO, called SDSS 1044-0125, has been detected. Light
which left the QSO just 1 billion years after the Universe was formed is
only now reaching us. The X-ray observations were made by theXMM-Newton X-ray observatory and were
lead by Dr. Neil Brandt of Penn State. The
XMM-Newton image of QSO SDSS 1044-0125 is shown above; the QSO is the
weak source at the center. Astronomers do not yet understand why the X-ray
emission from this source is so weak. It may be that the QSO is gobbling
surrounding matter at such a high rate that not even the X-ray emission can
escape.
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Page Author: Dr. Michael F.
Corcoran
Last modified May 26, 2001
