Spectra of faint sources in crowded fields with FRODOSpec on the Liverpool Robotic Telescope

TL;DR

This paper evaluates FRODOSpec's ability to observe faint sources in crowded fields, introducing a new data processing software that improves spectral accuracy for complex astronomical targets.

Contribution

The paper presents L2LENS, a novel processing software that enhances FRODOSpec's performance in crowded fields and for faint sources, addressing issues like cosmic rays and atmospheric effects.

Findings

L2LENS improves spectral accuracy for faint, crowded field sources.

FRODOSpec can provide valuable data for complex astronomical targets.

The method demonstrates potential for robotic telescope observations.

Abstract

We check the performance of the FRODOSpec integral-field spectrograph for observations of faint sources in crowded fields. Although the standard processing pipeline L2 yields too noisy fibre spectra, we present a new processing software (L2LENS) that gives rise to accurate spectra for the two images of the gravitationally lensed quasar Q0957+561. Among other things, this L2LENS reduction tool accounts for the presence of cosmic-ray events, scattered-light backgrounds, blended sources, and chromatic source displacements due to differential atmospheric refraction. Our non-standard reduction of Q0957+561 data shows the ability of FRODOSpec to provide useful information on a wide variety of targets, and thus, the big potential of integral-field spectrographs on current and future robotic telescopes.