On-sky Performance of a High Resolution Silicon Immersion Grating Spectrometer Jian Ge, Scott Powell, Bo Zhao, Sidney Schofield, Frank Varosi, Craig Warner, Jian Liu, Sirinrat Sithajan, Louis Avner, Hali Jakeman, Jakob A. Gittelmacher & William A. Yoder Department of Astronomy, University of Florida Matthew Muterspaugh, Michael Williamson & J. Edward Maxwell Center of Excellence in Information Systems, Tennessee State University High resolution infrared spectroscopy has been a major challenging task to accomplish in astronomy due to the enormous size and cost of IR spectrographs built with traditional gratings. A silicon immersion grating, due to its over three times high dispersion over a traditional reflective grating, offers a compact and low cost design of new generation IR high resolution spectrographs. Here we report the on-sky performance of the first silicon immersion grating spectrometer, called Florida IR Silicon immersion grating spectromeTer (FIRST), commissioned at the 2-meter Automatic Spectroscopic Telescope (AST) of Fairborn Observatory in Arizona in October 2013. The measured spectral resolution is R=50,000 with a 50 mm diameter spectrograph pupil and a blaze angle of 54.7 degree. The 1.4-1.8 m wavelength region (the Red channel) is completely covered in a single exposure with a 2kx2k H2RG IR array while the 0.8- 1.35 m region is nearly completely covered by the cross-dispersed echelle mode (the Blue channel) at R=50,000 in a single exposure. The instrument is operated in a high vacuum (about 1 micro torr) and cryogenic temperatures (the bench at 189K and the detector at 87K) and with a precise temperature control. It is primarily used for high precision Doppler measurements (~3 m/s) of low mass M dwarf stars for the identification and characterization of extrasolar planets. A plan for a high cadence and high precision survey of habitable super-Earths around ~150 nearby M dwarfs and a major upgrade with integral field unit low resolution spectroscopy are also introduced. Key words: High resolution, silicon immersion grating, robotic telescope, Doppler, infrared, exoplanets, spectrograph and M dwarfs. 1. Introduction One of the most important questions in all of astrophysics is “How common are Earth-like planets?” One way to answer this question with currently available technology is to look where the signal of an Earth-like planet would be strongest—M dwarfs. Low-mass planets in the habitable zones (HZs) of M-dwarfs yield larger and more frequent signals in both radial velocities (RV) and transits, and have a higher probability of transiting than similar objects around Sun-like stars. For this reason, dedicated searches for planets orbiting low-mass stars received strong support from the ExoPlanet Task Force and 2010 Decadal Survey. Of particular interest are M dwarfs later than M4, where the mass, size, and temperature of the stars begin to rapidly decrease. To date, most exoplanet searches targeting bright M dwarfs have been conducted at visible wavelengths 1,2,3 . Because the later type stars emit most of their light at redder wavelengths, only those earlier than M4 have been well studied. There are only 12 M4 or later type stars with V < 12 north of -30 degrees 4 . For comparison, there are about 300 nearby Ground-based and Airborne Instrumentation for Astronomy V, edited by Suzanne K. Ramsay, Ian S. McLean, Hideki Takami, Proc. of SPIE Vol. 9147, 91471A · © 2014 SPIE · CCC code: 0277-786X/14/$18 · doi: 10.1117/12.2057023 Proc. of SPIE Vol. 9147 91471A-1 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 10/31/2014 Terms of Use: http://spiedl.org/terms