Troubleshooting guide

1. Carry out the following steps at the telescope:
• Stop guiding (cf. Figure 8 of Guider GUI's).
• Turn down the guide camera gain (cf. Figure 3, ibid).
• Turn on the dome flatfield lamps (cf. Figure 11, ibid). The low lamps at full power (84 V) should give
~2400 ADU in JH-band with the JH grism in 30 s; if this sort of illumination level is not achievable in
a reasonably short integration time ( < 60 s), or if you want more signal, then you will need to use the
high lamps, but probably at a low voltage (24 V is the minimum).
• Turn dome tracking Off in the XTCS GUI (cf. Figure 9, ibid).
• Enable the MAIN button on PANEL B, to take the telescope out of AUTO (cf. Figure 9, ibid).
• Use the hand paddle (cf. Figure 10, ibid) to rotate the dome until a relatively blank section of silvery
dome is completely in front of the telescope.
If the target is too close to zenith, it will not be possible to use the side of the dome. Instead, record
the hour angle and declination of the telescope, then send the telescope to zenith and close the mirror
covers. Then close the dome and reopen the mirror covers and, finally, send the telescope back to the
recorded hour angle and declination. Set the dome so that the telescope is looking at the closed slit.
2. Set filename and exposure time. Use config.exposure.pl.
• Integration times of 30 s should give ~2400 ADU for JH- 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. Turn down the flatfield lamps to lower voltage, or turn them off.
• Flats at two different illumination levels are differenced to remove the dark current.
5. Take at least 5 flats with the lamps at the lower voltage. Use more.single.images.pl 5.
FLAMINGOS@2.1-m, Ver. 2.39, 2011 May 13 Page 32 of 46