Troubleshooting guide

The following commands are used for long slit and MOS plate spectroscopy:
On the Flamingos command line:
config.exposure.pl Set up the filename and exposure time.
config.filter.grism.decker.wheels.pl Set up and move Filter and Decker wheels
config.rel.mv.filter.grism.decker. Execute relative motion of Filter, Grism, or Decker wheel
wheels.pl
config.rel.mv.mos.wheel.pl Insert long slit or MOS plate.
config.mos.dither.kp4m.pl Set up the spectroscopy ABBA parameters.
dither.mos.kp4m.pl Take the spectroscopy ABBA data.
set.bias.pl Change bias for imaging or spectroscopy.
tweak.decker.pl <delta_angle> Adjust the Decker wheel position by angular increment.
tweak.mos.pl <delta_angle> Adjust the MOS wheel position by angular increment.
At the iraf cl prompt:
imexam Measure slit profiles and stellar centers (keys: a, x, g, i).
xbox Align a MOSplate (keys: q, f, g).
B. Preliminary Setup
Our experience with FLAMINGOS leads us to note that the efficiency of setting up on targets for spectroscopy
can be significantly improved by carrying out some preliminary work during the afternoon or at the beginning of
a spectroscopic run. Unlike an optical spectrograph, FLAMINGOS has no facility for viewing the field on the
slit, and target acquisition must be carried out by imaging through the slit onto the science array. Fortunately,
the motions of the Decker and MOS wheels appears to be quite reproducible, and the relative motion scripts
incorporate backlash removal, so it is possible to measure the location of the slit apertures on the array prior to
observing and move the target to the appropriate detector coordinates, and then move the slit into the beam with
confidence that it will be close enough to be centered up. This strategy greatly reduces the number of time-
consuming wheel motions.
• During the afternoon, after the masks are loaded, the support astronomer should check the orientation
of the masks with respect to the columns of the array by taking images in the Ks filter and tweak the
zero point of the MOS wheel motion using the ufmotor commands until the masks are precisely aligned
with the columns of the array. The mask stepper motor positions are sufficiently accurate so that
alignment of one mask should result in the other masks being aligned to within 3 – 4 pixels over their
length.
• Once this is done, the support astronomer or the observer should cycle through the masks and measure
the [x,y] position on the array of the center of the largest alignment hole in the MOS masks and/or the
center of the long slit and note these positions. This will save a lot of time during the night.
• If doing spectroscopy with one of the long slits in the MOS wheel (not one of the masks), move the
Decker wheel to the slit position and use the command tweak.decker.pl so that the image of the decker
aperture is centered on the location of the slit which will be used for spectroscopy.
• If one is doing spectroscopy with a MOS mask or one of the slit masks mounted in a MOS mask
position, set the Decker wheel to the mos position. The 3 × 10 arcmin field is adequate for initial
acquisition, and it is not necessary to move this wheel during the night.
• During the mask design process, it is very helpful if at least one of the alignment boxes can be made
significantly oversize, say 25 arcsec square. This makes it much easier to acquire at least one of the
alignment stars without iterating between the imaging and mask positions of the MOS wheel.
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