Wavelength calibration with PMAS at 3.5 m Calar Alto Telescope using a tunable astro-comb

J. M. Chavez Boggio*, T. Fremberg, D. Bodenmüller, C. Sandin, M. Zajnulina, A. Kelz, D. Giannone, M. Rutowska, B. Moralejo, M. M. Roth, M. Wysmolek, H. Sayinc

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

On-sky tests conducted with an astro-comb using the Potsdam Multi-Aperture Spectrograph (PMAS) at the 3.5 m Calar Alto Telescope are reported. The proposed astro-comb approach is based on cascaded four-wave mixing between two lasers propagating through dispersion optimized nonlinear fibers. This approach allows for a line spacing that can be continuously tuned over a broad range (from tens of GHz to beyond 1 THz) making it suitable for calibration of low- medium- and high-resolution spectrographs. The astro-comb provides 300 calibration lines and his line-spacing is tracked with a wavemeter having 0.3 pm absolute accuracy. First, we assess the accuracy of Neon calibration by measuring the astro-comb lines with (Neon calibrated) PMAS. The results are compared with expected line positions from wavemeter measurement showing an offset of ∼5–20 pm (4%–16% of one resolution element). This might be the footprint of the accuracy limits from actual Neon calibration. Then, the astro-comb performance as a calibrator is assessed through measurements of the Ca triplet from stellar objects HD3765 and HD219538 as well as with the sky line spectrum, showing the advantage of the proposed astro-comb for wavelength calibration at any resolution.

Original languageEnglish
Pages (from-to)186-193
Number of pages8
JournalOptics Communications
Volume415
DOIs
Publication statusPublished - 15 May 2018

    Fingerprint

Keywords

  • Astronomy
  • Optical frequency comb
  • Spectrograph
  • Wavelength calibration

Cite this

Chavez Boggio, J. M., Fremberg, T., Bodenmüller, D., Sandin, C., Zajnulina, M., Kelz, A., Giannone, D., Rutowska, M., Moralejo, B., Roth, M. M., Wysmolek, M., & Sayinc, H. (2018). Wavelength calibration with PMAS at 3.5 m Calar Alto Telescope using a tunable astro-comb. Optics Communications, 415, 186-193. https://doi.org/10.1016/j.optcom.2018.01.007