- O/IR System
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Phoenix is a cryogenic, long slit, high resolution (R~50000), near infrared (1 - 5 micron) spectrograph designed for used at the f/15 focus of 2 to 8-m class telescopes.
At Gemini the limiting magnitude at K is about 12 depending on conditions. The limiting magnitude is brighter in the thermal IR, about 7 at M. Phoenix IS NOT cross-dispersed with a single integration spectral coverage of 0.5 percent (= 1550 km s-1 = 115 A at 23000 A = 22 cm-1 at 4300 cm-1) observed in one integration. Phoenix IS long slit with a slit length of 15 arcseconds on Gemini.
Phoenix was designed and built at NOAO-Tucson and is maintained and operated by NOAO staff. The Phoenix vacuum vessel is about 0.7-m in diameter and 1.3-m high and weighs about 680 kg. It contains seven externally controlled moving parts and 32 optical elements. Development of Phoenix took place at Kitt Peak in the late 1990s with a fully functional instrument shipped to Gemini in 2001. In 2011 Phoenix was shipped back to Kitt Peak in order to make space on the Gemini South ISS for F2. With the closure of the open access Kitt Peak facilities Phoenix was shipped back to Gemini South in early 2016 for use as a visitor instrument.
Potential users are reminded that spectra must be taken in pairs nodded along the slit with a standard observation consisting of an ABBA set. Thus if a 1 hour exposure is desired in the ITC enter 3600 seconds for the integration time and 900 seconds for the maximum time per single exposure. In the thermal infrared (red of 2.5 microns) the maximum exposure time is limited by background radiation from the telluric lines. At 4.6 microns the maximum exposure is 60 seconds. Thermal IR observations are also notoriously condition sensitive.
The overhead to move the telescope and align a point source in the slit will be on the order of 10-15 minutes per target. Acquisitions in the thermal IR near limiting magnitudes will be difficult and more time should be scheduled in this case.
Updated 2015 Aug 19
Last updated or reviewed April 26, 2017.