ARGOS at the LBT. Binocular laser guided ground layer adaptive optics

TL;DR

ARGOS is a ground-layer adaptive optics system at LBT that uses laser guide stars to significantly improve near-infrared imaging resolution, enabling advanced scientific observations of various astronomical objects.

Contribution

This paper presents the final technical setup and performance of ARGOS, a novel laser-guided ground-layer adaptive optics system at LBT, enhancing infrared imaging capabilities.

Findings

PSF size reduced by a factor of 2-3 under regular conditions

Enhanced scientific observations in near-infrared with high spatial and spectral resolution

First scientific results on local and high-redshift objects demonstrate ARGOS capabilities

Abstract

Having completed its commissioning phase, the Advanced Rayleigh guided Ground-layer adaptive Optics System (ARGOS) facility is coming online for scientific observations at the Large Binocular Telescope (LBT). With six Rayleigh laser guide stars in two constellations and the corresponding wavefront sensing, ARGOS corrects the ground-layer distortions for both LBT 8.4m eyes with their adaptive secondary mirrors. Under regular observing conditions, this set-up delivers a point spread function (PSF) size reduction by a factor of ~2--3 compared to a seeing-limited operation. With the two LUCI infrared imaging and multi-object spectroscopy instruments receiving the corrected images, observations in the near-infrared can be performed at high spatial and spectral resolution. We discuss the final ARGOS technical set-up and the adaptive optics performance. We show that imaging cases with ground-layer adaptive optics (GLAO) are enhancing several scientific programmes, from cluster colour magnitude diagrams and Milky Way embedded star formation, to nuclei of nearby galaxies or extragalactic lensing fields. In the unique combination of ARGOS with the multi-object near-infrared spectroscopy available in LUCI over a 4x4 arcmin field of view, the first scientific observations have been performed on local and high-z objects. Those high spatial and spectral resolution observations demonstrate the capabilities now at hand with ARGOS at the LBT.