A new algorithm for sky extraction for multi-fiber instrument

TL;DR

This paper introduces a novel sky subtraction algorithm for fiber-fed spectrographs, enabling high-precision removal of sky background in multi-object observations for future large telescopes.

Contribution

The paper presents a new sky subtraction method that accurately reconstructs sky background fluctuations, improving precision over existing techniques for fiber-fed spectrographs.

Findings

Achieves 1% sky subtraction accuracy in mono-fiber mode.

Attains 0.3-0.4% accuracy in integral-field-unit observations.

Applicable to large FoV of 7x7 arcmin^2.

Abstract

We present a new method to subtract sky light from faint object observations with fiber-fed spectrographs. The algorithm has been developed in the framework of the phase A of OPTIMOS-EVE, an optical-to-IR multi-object spectrograph for the future european extremely large telescope (E-ELT). The new technique overcomes the apparent limitation of fiber-fed instrument to recover with high accuracy the sky contribution. The algorithm is based on the reconstruction of the spatial fluctuations of the sky background (both continuum and emission) and allows us to subtract the sky background contribution in an FoV of $7\times7 arcmin^2$ with an accuracy of 1% in the mono-fibers mode, and 0.3-0.4% for integral-field-unit observations.