New methods to improve the decontamination of slitless spectra

TL;DR

This paper introduces four innovative decontamination methods for slitless spectra in space missions, utilizing two approaches that consider multiple dispersion directions, and demonstrates their effectiveness with realistic Euclid-like data.

Contribution

It presents two new approaches and four methods for decontaminating slitless spectra, integrating multiple dispersion directions and combining decontamination with deconvolution.

Findings

Methods successfully decontaminate spectra in noisy, realistic data

Approaches effectively handle multiple dispersion directions

Proven improvements over existing techniques

Abstract

This paper proposes four new methods to decontaminate spectra of stars and galaxies resulting from slitless spectroscopy used in many space missions such as Euclid. These methods are based on two distinct approaches and simultaneously take into account multiple dispersion directions of light. The first approach, called the local instantaneous approach, is based on an approximate linear instantaneous model. The second approach, called the local convolutive approach, is based on a more realistic convolutive model that allows simultaneous decontamination and deconvolution of spectra. For each approach, a mixing model was developed that links the observed data to the source spectra. This was done either in the spatial domain for the local instantaneous approach or in the Fourier domain for the local convolutive approach. Four methods were then developed to decontaminate these spectra from the mixtures, exploiting the direct images provided by photometers. Test results obtained using realistic, noisy, Euclid-like data confirmed the effectiveness of the proposed methods.