The Rutgers Fabry-Perot (RFP) imaging spectrometer is being withdrawn from service as of next semester (2000A), and no proposals for using the instrument will be accepted. The RFP has had a productive thirteen-year career at Tololo. Its first use was to measure the Ha rotation curve of NGC 7552 by R. Schommer, M. Phillips, and night assistant P. Ugarte on the 1.5-m on 23 October 1986; its final observation was of the kinematics of stars in the Milky Way center by T. Williams and night assistant P. Ugarte on the 1.5-m on 21 June 1999. In the intervening years, a wide variety of imaging spectroscopy has been carried out using the unique capabilities of the instrument.
CTIO will not be without an imaging Fabry-Perot instrument for long, however. A successor to the RFP is being constructed at Rutgers and should be in operation for semester 2001A. This new instrument, the Rutgers Advanced Spectroscopic Imager (RASI), will offer significant new capabilities. In addition to the two spectroscopic resolutions provided by the RFP (R = 8000 and 2500), a third etalon will provide lower resolution (variable from R = 400 to 1200). The linear field of view will be twice that of the RFP, making the instrument 4 times faster for extended objects. The RASI will operate at the 1.5-m f/13.5 focus and the Blanco f/14 focus, and will be suitable for use on both SOAR and Gemini in the future; the internal optics of the instrument will fully exploit the excellent imaging performance of these telescopes. A monitor channel will measure the atmospheric transparency during observations, to allow use of the RASI in non- photometric conditions with no loss of accuracy; the monitor CCD will also generate error signals for fast guiding/tip-tilt correction. A new filter suite and dual-etalon operation will allow the use of the RASI at any wavelength from 4700Å to 8700Å at all resolutions, with no need for additional blocking filters. Updates and status of RASI will be available on the web as the project nears completion.
Ted Williams (Rutgers University),
Bob Schommer (bschommer@noao.edu), CTIO