Steven M. Kahn
Physics Department Chair
Columbia University
 

The XMM-Newton Observatory is a major facility-class X-ray space observatory
developed by the European Space Agency.  It was launched on an ARIANE V
rocket in December of last year.  The satellite carries three large
grazing incidence telescopes and associated scientific instruments,
including a Reflection Grating Spectrometer (RGS) partially designed and
built at Columbia University.  The RGS has provided some of the first
high resolution spectra of cosmic sources in the soft X-ray band, which
includes a wealth of atomic transitions of multiply charged ions of the
abundant elements carbon through iron.  Data have already been acquired
on a diverse array of sources ranging from normal stars to distant
quasars.  I will review the details of the instrument and discuss
a few examples where the newly acquired X-ray spectra have significantly
challenged our conventional understanding of the sources involved.