Pre-imaging observations will be performed about 1-2 month
before the actual target spectroscopy.
This observation is made by observatory staffs.
Observers are requested to submit target coordinate lists and finding
charts before the pre-imaging.
Note: the observatory staff will perform not only your pre-imagings but
also for other's in a same night, your good finding charts and good
instructions (required magnitude depth/exposure time, etc.) will be greatly
appreciated to avoid any careless mistakes.
Observers will receive FITS files of the pre-imaging data.
Observers will find their favorite targets and measure their coordinates
on the FOCAS image.
At this time, a pair of two CCD images (chip1 and 2) must be combined
by using the software provided by FOCAS team.
Observers will make (an) object list(s) which describe(s)
the target coordinates, slit width, slit length, and priorities, etc. in
pixel units.
Observers will design their own mask(s) based on the object
lists to make the slit list(s).
The slit list is used for cutting the slits with the laser cutting equipment
at the Subaru control building at Mauna Kea Summit.
Observers should submit the slit lists to the observatory
staff before the due time specified by the observatory staff.
Observatory staff will make your masks based on your slit lists before the MOS observation time.
MOS masks will be installed into the FOCAS at the evening
of the observation by the observatory staffs.
- Note: Due to the mechanical limitation of the MOS mask exchange system, MOS (and long-slit) pointing at EL<30 could not be made. However, the telescope can track the target even at EL<30 unless no mask/slit insertion/removal is conducted (though EL<25 is not recommended generally due to poor sky conditions, e.g., bad seeing, at low EL sky).