November 23, 2006
On November 9, about 2/3 of imaging area of XIS2, one of the
X-ray CCD cameras, became suddenly unusable. All other sensors,
XIS0, 1, 3, are fine. Since there was a concern that the start
of spaced-row charge injection (SCI) might have triggered the
problem, we temporally stopped the SCI just after the trouble.
However, after extensive analysis and in-orbit and ground tests,
we concluded the SCI is not related to the trouble. We will
soon resume the SCI step by step.
Our attempts to recover XIS2 have so far proven unsuccessful,
but we will continue our efforts to identify the cause of the
problem. In the mean time, we will increase the exposure
times of Priority A targets of cycle-1 GO observations by 25 %,
and use them as the observation-completion criteria. However
we will not increase those of Priority B and C targets, thus
the observation-completion criteria for Priorities B and C
remain the same.
We ask cycle-2 proposers to perform proposal simulations assuming
four XIS sensors. We will consider adjusting observation times
according to evaluation by the selection boards.
Suzaku Project Manger
ISAS/JAXA Department of High Energy Astrophysics
Last Modified: Thursday, 23-Nov-2006 11:23:35 JST