Journal article
Holistic spectroscopy: complete reconstruction of a wide-field, multiobject spectroscopic image using a photonic comb
Monthly notices of the Royal Astronomical Society, Vol.480(4), pp.5475-5494
11/11/2018
DOI: 10.1093/mnras/sty2175
Abstract
The primary goal of Galactic archaeology is to learn about the origin of the Milky Way from the detailed chemistry and kinematics of millions of stars. Wide-field multifibre spectrographs are increasingly used to obtain spectral information for huge samples of stars. Some surveys (e.g. GALAH) arc attempting to measure up to 30 separate elements per star. Stellar abundance spectroscopy is a subtle art that requires a very high degree of spectral uniformity across each of the fibres. However, wide-field spectrographs are notoriously non-uniform due to the fast output optics necessary to image many fibre outputs on to the detector. We show that precise spectroscopy is possible with such instruments across all fibres by employing a photonic comb - a device that produces uniformly spaced spots of light on the CCD to precisely map complex aberrations. Aberrations are parametrized by a set of orthogonal moments with similar to 100 independent parameters. We then reproduce the observed image by convolving high-resolution spectral templates with measured aberrations as opposed to extracting the spectra from the observed image. Such a forward modelling approach also trivializes some spectroscopic reduction problems like fibre cross-talk, and reliably extracts spectra with a resolution similar to 2.3 times above the nominal resolution of the instrument. Our rigorous treatment of optical aberrations also encourages a less conservative spectrograph design in the future.
Details
- Title: Subtitle
- Holistic spectroscopy: complete reconstruction of a wide-field, multiobject spectroscopic image using a photonic comb
- Creators
- Janez Kos - The University of SydneyJoss Bland-Hawthorn - The University of SydneyChristopher H. Betters - The University of SydneySergio Leon-Saval - The University of SydneyMartin Asplund - Australian National UniversitySven Buder - Max Planck Institute for AstronomyAndrew R. Casey - Monash UniversityValentina D'Orazi - Osserv Astron Padova, Ist Natl Astrofis, Vicolo Osservatorio 5, I-35122 Padua, ItalyGayandhi de Silva - The University of SydneyKen Freeman - Australian National UniversityGeraint Lewis - The University of SydneyJane Lin - Australian National UniversitySarah L. Martell - ARC Centre of Excellence for All-sky AstrophysicsKatharine Schlesinger - Australian National UniversitySanjib Sharma - The University of SydneyJeffrey D. Simpson - Australian Astronomical ObservatoryDaniel Zucker - Macquarie UniversityTomaz Zwitter - University of LjubljanaMichael Hayden - The University of SydneyJonathan Horner - University of Southern QueenslandDavid M. Nataf - Johns Hopkins UniversityYuan-Sen Ting - Princeton University
- Resource Type
- Journal article
- Publication Details
- Monthly notices of the Royal Astronomical Society, Vol.480(4), pp.5475-5494
- DOI
- 10.1093/mnras/sty2175
- ISSN
- 0035-8711
- eISSN
- 1365-2966
- Publisher
- Oxford Univ Press
- Number of pages
- 20
- Grant note
- Allan C. and Dorothy H. Davis Fellowship DP150104667; DP180101791; DP160100637 / Australian Research Council P1-0188 / Slovenian Research Agency; Slovenian Research Agency - Slovenia
- Language
- English
- Date published
- 11/11/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984701824802771
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