title: A complex multi-notch astronomical filter to suppress the bright infrared sky.
abstract: A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.
authors.affiliation: Sydney Institute for Astronomy, School of Physics, University of Sydney, Camperdown, New South Wales 2006, Australia. jbh@physics.usyd.edu.au
authors.forename: J
authors.initials: J
authors.lastname: Bland-Hawthorn
authors.forename: S C
authors.initials: SC
authors.lastname: Ellis
authors.forename: S G
authors.initials: SG
authors.lastname: Leon-Saval
authors.forename: R
authors.initials: R
authors.lastname: Haynes
authors.forename: M M
authors.initials: MM
authors.lastname: Roth
authors.forename: H-G
authors.initials: HG
authors.lastname: Löhmannsröben
authors.forename: A J
authors.initials: AJ
authors.lastname: Horton
authors.forename: J-G
authors.initials: JG
authors.lastname: Cuby
authors.forename: T A
authors.initials: TA
authors.lastname: Birks
authors.forename: J S
authors.initials: JS
authors.lastname: Lawrence
authors.forename: P
authors.initials: P
authors.lastname: Gillingham
authors.forename: S D
authors.initials: SD
authors.lastname: Ryder
authors.forename: C
authors.initials: C
authors.lastname: Trinh
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy / Q000295:instrumentation / Q000379:methods*; D005118:Extraterrestrial Environment; D055608:Galaxies; D007259:Infrared Rays; D055096:Optical Devices; D017785:Photons; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D061351:Telescopes