Probing the Interaction Between Comets and the Solar
Dennis Bodewits, R. Hoekstra, and A.G.G.M.
KVI Atomic Physics
9747 AA Groningen
*Kapteyn Astronomical Institute/SRON
Comets are bright emitters in X-ray and Far-Ultraviolet (XUV).
The main driver of this emission is charge exchange between solar
wind ions and neutrals in the cometary coma. We study these reactions
in the laboratory and use our results to model cometary XUV emission.
Recent observations show that cometary XUV emission depends
on properties of both the comet (mass loss, composition, distance
to the sun) and the solar wind (speed, composition). The understanding
of their interaction requires a deep insight in the atomic processes
that constitute it. Unfortunately, there are still many gaps
in our knowledge about some of the crucial charge exchange reactions
in cometary atmospheres. Two examples are collisions involving
Hydrogen-like highly charged ions and collisions between solar
wind ions and atomic oxygen.
An interdisciplinary effort is therefore called for to turn
the next generation cometary XUV observations into valuable,
remote diagnostics for studying solar system plasmas.