  X-ray emission generated through solar-wind charge exchange (SWCX) is known
to contaminate X-ray observation data, the amount of which is often significant
or even dominant, particularly in the soft X-ray band, when the main target is
comparatively weak diffuse sources, depending on the space weather during the
observation. In particular, SWCX events caused by interplanetary coronal mass
ejections (ICMEs) tend to be spectrally rich and to provide critical
information about the metal abundance in the ICME plasma. We analyzed the
SN1006 background data observed with Suzaku on 2005 September 11 shortly after
an X6-class solar flare, signatures of which were separately detected together
with an associated ICME. We found that the data include emission lines from a
variety of highly ionized ions generated through SWCX. The relative abundances
of the detected ions were found to be consistent with those in past ICME-driven
SWCX events. Thus, we conclude that this event was ICME-driven. In addition, we
detected a sulfur XVI line for the first time as one from the SWCX emission,
the fact of which suggests that it is the most spectrally-rich SWCX event ever
observed. We suggest that observations of ICME-driven SWCX events can provide a
unique probe to study the population of highly-ionized ions in the plasma,
which is difficult to measure in currently-available in-situ observations.
