Troubleshooting guide

science target spectra. The alignment of the slit, filter and grism should not have been changed from that used
for the science target. It should take 5 – 10 minutes to complete.
1. Have the telescope operator do the following:
• Pause guiding. To do so, just hit the OFF button for the guider.
• Turn down the guide camera gain.
• Select the Comps mirror position.
• Select the Dim Quartz lamp at 100% power.
2. Set filename and exposure time. Use config.exposure.pl.
• Integration times of 10 – 30 s should suffice for JH-band and HK-band spectroscopy.
• Take a test exposure (singleimage.pl). The counts should be < 25,000 ADU for wavelengths < 2.4 μm.
• With 30 second integration times, it is possible to do 8 reads, if you can accept the little bit of extra
overhead.
3. Take at least 5 flats with the lamps on. Use more.single.images.pl 5.
4. Have the telescope operator turn down the quartz lamp, or turn it off.
• Leave the Comp mirror in place.
• Flats at two different illumination levels are differenced to remove the dark current.
5. Take at least 5 flats with the lamps off. Use more.single.images.pl 5.
6. Have the telescope operator turn on the HeNeAr lamp.
7. Take a wavelength calibration image.
• Integration times of 100 s should work for JH-band spectroscopy.
• We usually use only sky lines (OH) for wavelength calibration in the HK-band, although there are a
number of HeNeAr lines in this band.
8. Take a wavelength calibration image with the lamp off.
If you wish to resume guiding on the science target for additional observations without rechecking the alignment
(this may or may not work):
1. Have the telescope operator do the following:
• Turn off calibration lamps.
• Take out the Comp mirror (put it back to the THRU position).
• Resume guiding. NOTE:
• When guiding is suspended the guide star may move slightly out of the guide box.
• Make certain the telescope operator DOES NOT WARP the guide box onto the star to resume
guiding. Doing so will move the guide box to the star's present location, and the telescope will be
guiding at the wrong place and your target will no longer be optimally aligned on the slit.
• If the star has moved out of the guide box, the telescope operator should:
• Leave the OFF button pushed on the GUI.
• Tweak the telescope pointing with the hand paddle to move the star into the guide box.
• Once the star is in the box, resume guiding by pushing the LOCK button on the GUI.
• Once the star is again in the guide box, wait a minute to watch the guide software capture the star's
location, and move it back to the guiding center within the guide box.
To obtain dome flats, position the telescope at the HA midpoint of the target observation (as for the quartz
flats).
1. Have the telescope operator do the following:
• Turn off telescope tracking and position the telescope at the HA midpoint of the target observation.
• Turn off dome tracking.
• Manually move the dome so that it completely blocks the telescope aperture.
FLAMINGOS@4-m, Ver. 2.39, 2013 April 23 Page 32 of 47