GNOSIS: A novel near-infrared OH suppression unit at the AAT
conference contribution
posted on 2024-08-06, 09:21 authored by C. Q. Trinh, S. C. Ellis, J. S. Lawrence, A. J. Horton, J. Bland-Hawthorn, S. G. Leon-Saval, J. Bryant, S. Case, M. Colless, Warrick CouchWarrick Couch, K. Freeman, L. Gers, Karl GlazebrookKarl Glazebrook, R. Haynes, S. Lee, H. G. Löhmannsröben, S. Miziarski, J. O'Byrne, W. Rambold, M. M. Roth, B. Schmidt, K. Shortridge, S. Smedley, C. G. Tinney, P. Xavier, J. Zheng, Ian S. McLean, Suzanne K. Ramsay, Hideki TakamiGNOSIS has provided the first on-telescope demonstration of a concept to utilize complex aperioidc fiber Bragg gratings to suppress the 103 brightest atmospheric hydroxyl emission doublets between 1.47-1.7 μm. The unit is designed to be used at the 3.9-meter Anglo-Australian Telescope (AAT) feeding the IRIS2 spectrograph. Unlike previous atmospheric suppression techniques GNOSIS suppresses the lines before dispersion. We present the results of laboratory and on-sky tests from instrument commissioning. These tests reveal excellent suppression performance by the gratings and high inter-notch throughput, which combine to produce high fidelity OH-free spectra.
