PRAXIS: a near infrared spectrograph optimised for OH suppression

• DOI: 10.1117/12.2232115
• Publication Date: 2016-08-09T18:35:06Z
• Authors: S. C. Ellis; S. Bauer; J. Bland-Hawthorn; S. Case; R. Content; T. Fechner; D. Giannone; R. Haynes; E. Hernandez; A. J. Horton; U. Klauser; J. S. Lawrence; S. G. Leon-Saval; E. Lindley; H.-G. Löhmannsröben; S.-S. Min; N. Pai; M. Roth; K. Shortridge; Nicholas F. Staszak; Julia Tims; Pascal Xavier; Ross Zhelem
• Keywords: Praxis; Fiber Bragg Grating

Atmospheric emission from OH molecules is a long standing problem for near-infrared astronomy. PRAXIS unique spectrograph, currently in the build-phase, which fed by fibre array that removes background. The suppression achieved with Bragg gratings, were tested successfully on GNOSIS instrument. will use same gratings as first implementation, and new, less expensive more efficient, multicore second implementation. lines are suppressed factor of ~1000, expected increase signal-to-noise interline regions compared to ~ 9 17 new gratings. enable full exploitation time, was not due high thermal emission, low spectrograph transmission, detector noise. have extremely through cooling all significantly emitting parts, including fore-optics, length fibre, slit, an optical design minimises leaks outside spectrograph. achieve noise Hawaii-2RG detector, throughput efficient VPH based scientific aims instrument determine absolute level continuum observations individual objects via IFU. be installed AAT, then later 8m class telescope.