| About ROSAT |
ROSAT Home Page | ROSAT Images |
|---|
While auroral X-rays are a specific example of STEs,
they deserve a special note.
They can completely dominate a pointed observation, with count
rates exceeding 200 counts s 
in particularly bad geometries.
Not surprisingly, the most sensitive geometries for auroral
X-ray contamination are where the satellite is passing near
the northern or southern particle belts and the observation is
of a far northerly or southerly target,
which requires a large zenith angle.
In this geometry, the line of sight can pass through the
particle belts at relatively low altitudes where the atmospheric
density (and therefore number of scatterers) is large.