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PHOENIX INFRARED HIGH-RESOLUTION SPECTROGRAPH

AT THE KPNO 4-m

Proposals for 2015A due on September 25, 2014

Phoenix has been used successfully at KPNO since its return from Gemini South in late 2012. The 2015A semester will be the final offering of Phoenix at the KPNO 4-m.


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Phoenix at the KPNO 4-m Telescope

For 2015A, Phoenix is being offered only at the KPNO 4-m telescope; this will be the final semester for Phoenix.

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 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.

The integration time calculators have been calibrated based on a combination of KPNO and Gemini experience. Further refinements will take place as additional Kitt Peak data are collected. Remember that results at the telescope depend on observing conditions. The ITCs assume clear weather.

ITC for the KPNO Mayall 4 m


Phoenix Basics

Phoenix is a cryogenic, long slit, high resolution infrared spectrograph designed for used at the f/15 focus of the KPNO 2.1-m, the Mayall, Blanco, and SOAR 4-m, and the Gemini 8-m telescopes. Phoenix was designed and built at NOAO-Tucson to extend high-resolution spectroscopy into the 1-5 micron region of the infrared. The driving design goal was for spectroscopy in the 1.5-2.5 micron region at resolution of 50,000 or higher to a limiting magnitude K~10 with a 2-meter telescope.

Phoenix uses an Aladdin II 1024x1024 InSb array as the detector and is operable throughout the range of sensitivity of InSb, 1-5 microns. The grating is a 63.4 degree echelle with 32 lines per millimeter. The spectrograph is NOT cross dispersed with the spectral coverage limited by the 1024 pixels in the dispersion direction. This corresponds to ~1500 km s-1 in velocity space. Echelle orders are selected using order sorting filters . A number of filters are available but filters are not available for all possible orders covering the 1-5 micron range. Slits of width 2, 3, and 4 pixels are available for resolution in the range 50000-70000. Most users select the 4 pixel wide slit, which maximizes throughput. The (4 pixel) slit width and length is 0.7 x 28 arcseconds at the 4-m telescope. Flat field and hollow cathode lamps are installed in the instrument interface assembly.

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 the fully functional instrument shipped to Gemini in 2001. In late 2011 Phoenix was shipped back to Kitt Peak. Operation at Kitt Peak is similar to that at Gemini. The most important changes (other than the decreased telescope aperture!) are (1) tracking and pointing on the KPNO telescopes are not nearly as precise as at Gemini, (2) DIQ at these telescopes is about a factor of two worse than at Gemini. The plate scale is of course changed due to the change of aperture.

This Web site contains a quick reference page, a draft user manual, integration time calculators (above), various reports on the instrument, and other associated documents supporting the use of the spectrograph.

Please contact Ken Hinkle (hinkle@noao.edu) for additional information.

Historical performance of Phoenix on Gemini

Phoenix Documentation

Papers Describing Phoenix

Phoenix NOAO Newsletter Articles


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Updated 22 July 2014