title: Demonstration of on-sky calibration of astronomical spectra using a 25 GHz near-IR laser frequency comb.
abstract: We describe and characterize a 25 GHz laser frequency comb based on a cavity-filtered erbium fiber mode-locked laser. The comb provides a uniform array of optical frequencies spanning 1450 nm to 1700 nm, and is stabilized by use of a global positioning system referenced atomic clock. This comb was deployed at the 9.2 m Hobby-Eberly telescope at the McDonald Observatory where it was used as a radial velocity calibration source for the fiber-fed Pathfinder near-infrared spectrograph. Stellar targets were observed in three echelle orders over four nights, and radial velocity precision of ∼10 m/s (∼6 MHz) was achieved from the comb-calibrated spectra.
authors.affiliation: Department of Physics, University of Colorado, Boulder, CO, USA. ycasg@colorado.edu
authors.forename: Gabriel G
authors.initials: GG
authors.lastname: Ycas
authors.forename: Franklyn
authors.initials: F
authors.lastname: Quinlan
authors.forename: Scott A
authors.initials: SA
authors.lastname: Diddams
authors.forename: Steve
authors.initials: S
authors.lastname: Osterman
authors.forename: Suvrath
authors.initials: S
authors.lastname: Mahadevan
authors.forename: Stephen
authors.initials: S
authors.lastname: Redman
authors.forename: Ryan
authors.initials: R
authors.lastname: Terrien
authors.forename: Lawrence
authors.initials: L
authors.lastname: Ramsey
authors.forename: Chad F
authors.initials: CF
authors.lastname: Bender
authors.forename: Brandon
authors.initials: B
authors.lastname: Botzer
authors.forename: Steinn
authors.initials: S
authors.lastname: Sigurdsson
mesh_terms: D001256:Astronomy / Q000295:instrumentation* / Q000592:standards*; D002138:Calibration; D007259:Infrared Rays; D038622:Internationality; D053844:Lasers, Solid-State / Q000592:standards*; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000592:standards*