The problem of atmospheric emission from OH molecules is a long standing problem for near-infrared astronomy. We are now close to solving this problem for the first time with the PRAXIS instrument. PRAXIS is a unique spectrograph which is fed by fibres that remove the OH background, and is optimised specifically to benefit from OH-Suppression. The OH suppression is achieved with fibre Bragg gratings, which were tested successfully on the GNOSIS instrument. The OH lines are suppressed by a factor of ∼1000, leading to a reduction of the integrated background of a factor 9. A future upgrade to multicore fibre Bragg gratings will further increase this reduction. PRAXIS has had two commissioning runs, with a third commissioning run planned for July 2019, which will be presented at the conference. PRAXIS has a measured throughput of 20 %, demonstrating high efficiency in an OH suppression instrument for the first time. Science verification observations of Seyfert galaxies demonstrate the potential of OH suppression.
|Title of host publication||Advances in Optical Astronomical Instrumentation 2019|
|Editors||Simon Ellis, Céline d'Orgeville|
|Place of Publication||Bellingham, Washington|
|Number of pages||2|
|Publication status||Published - 6 Jan 2020|
|Event||Advances in Optical Astronomical Instrumentation 2019 - Melbourne, Australia|
Duration: 9 Dec 2019 → 12 Dec 2019
|Name||Proceedings of SPIE|
|Conference||Advances in Optical Astronomical Instrumentation 2019|
|Period||9/12/19 → 12/12/19|
Bibliographical noteCopyright 2020 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
- Fibre Bragg gratings
- Near infrared
- OH suppression