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Phoenix is being offered on Gemini South in 2008B in both
queue and classical mode. For classical mode observations
the time must be in integer nights.
Phoenix will be offered on SOAR following its use on Gemini. This may
be late 2009.
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Phoenix is currently being offered in either queue or classical mode on Gemini South and is being supported by Gemini Staff (rather than NOAO staff as was the case before 2007). Classical time requests must be in integer nights. In classical mode an observer from the proposing team must be present for the observations. Classical observers will be supported by Gemini Staff.
Phoenix was delivered to Gemini South on September 10, 2001 and underwent commissioning on Gemini in December 2001. The first science run occurred in February 2002. The demonstration science project "Oxygen Abundance in the LMC" was carried out at that time. The results of this project have been published by Smith et al. (2002 AJ 124 3241). Phoenix is classified a `visitor' instrument on Gemini which imposes restrictions on the use. Potentially the most significant of these is that a minium total of 16 nights must be scheduled in each semester before Phoenix will be scheduled. To date reaching the minimum number of nights has not been a problem.
The performance of Phoenix on Gemini is described by the href="http://www.noao.edu/gateway/spectime/gemphx.html"> exposure time calculator. On Gemini K or H~14 at S/N~10 is possible in a total of 1 hour of integration under good conditions. Limiting magnitudes longwards of 2.5 microns are of course much brighter. Note that the longest exposure in the 4.6 micron window is only 30 seconds due to the large thermal background and with this exposure sufficient star signal must be recorded to extract the spectrum from the image. As a result in the 4.6 micron region the limiting magnitude is about M=+7 but is highly sensitive to the emissivity of both the telescope and atmosphere.
High signal-to-noise is possible in the non-thermal infrared in exposure times less than one hour for K=12 or brighter. By K=8 the exposure times are a few minutes. Similarly high signal-to-noise is possible at M brighter than 7. A limiting source of noise is electrical pick up from the telescope drives. This noise is only apparent at the limiting magnitudes and is somewhat variable. Gemini has reduced this noise and further improvements are expected. In any case, performance on Gemini is already impressive!
Proposers for classical time must include time for overheads and calibration observations in their time request.
Overheads: Typically 20 to 30 minutes are required to move the telescope to a new source and center the source on the slit. The telescope moves rapidly. Locking onto the guide star can take perhaps five minutes depending on conditions, the guide star brightness, image quality and the need to refigure the telescope, etc. Centering the source on the Phoenix slit is tedious and very experienced observers can not observe more than six bright stars in one hour. After the star is acquired near-infrared observations should allow about four additional minutes for readouts and nods. For programs requiring complex nods, e.g. maps of nebulae, or thermal infrared observations where the exposure time is at most a few minutes, 30 percent additional time should be allowed as overhead time.
Calibration observations: In classical mode the observer must allow time during the night for any reference star observations that are required. If standard bright reference stars will be used there is no need to list these stars in your proposal. However, you must allow adequate telescope time for standard star observations as well as flats and darks. Flats and dark taken during the night require about 10 minutes and there is no need to move the telescope. Tracking can be maintained during flat and dark exposures. Time must be allowed for changes in wavelength if these are required. Allow time for a set of flats and darks and about 5 minutes to set up a new filter and grating position. If the grating position must be set precisely to allow observations of spectral lines near the edges of the band pass, an extra 30 minutes should be allowed for a standard star to be acquired and the grating position checked.
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 KPNO and CTIO 4-m and the Gemini 8-m telescopes. Phoenix was designed and built at NOAO-Tucson to extend photon limited, high resolution, spectroscopy into the 1-5 micron region of the infrared. Design goals called for 2 micron region spectroscopy with the 2-meter telescope at resolution of 50,000 or higher to limiting magnitudes of ~10. With the installation of a photon counting array in February 2001 these goals were exceeded.
Phoenix uses an Aladdin 512x1024 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 giving a dispersion of about 2 x 105 per pixel. Slits of width 2, 3, and 4 pixels are available for resolution in the range 50000-80000. A hollow cathode wavelength calibration source is supplied with the instrument and image rotation and first order (tip-tilt) AO is a feature of the Gemini telescopes. The (4 pixel) slit width and length is 0.35 by 14 arcseconds on an 8-m telescope.
This Web site contains a FAQ, a user manual, various reports on the instrument, and other associated documents supporting the use of the spectrograph. The Phoenix vacuum vessel is about 0.7-m in diameter and 1.3-m high. It contains seven externally controlled moving parts and 32 optical elements. As might be expected for an instrument of this complexity, it has taken a considerable effort to understand the instrument and to optimize its performance. Significant improvement has been made in performance since the initial commissioning of the instrument. Progress is summarized in the Newsletter article attached below. The instrument as shipped to Gemini was fully mature and has been highly productive as the first high resolution spectrograph on a Gemini telescope and the first high resolution infrared spectrograph on a major southern hemisphere telescope. Please contact Ken Hinkle (hinkle@noao.edu) for additional information.
The NOAO long range plan has been to offer Phoenix at the 4 meter SOAR telescope. Phoenix, which was a visitor instrument at Gemini, would be a facility instrument at SOAR. However, delays at SOAR have jeopardized this plan. The Phoenix/SOAR exposure time calculator will allow you to envisage your project at SOAR. Feel free to express your interest in using SOAR to me and to the SOAR director. Regrettably if there is not interest expressed in using Phoenix at SOAR it will not happen.
Updated 7May2003
