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ARGOS is the Ground Layer Adaptive Optics system of the Large Binocular Telescope, on each side it uses three Laser Guide Stars, generated by Rayleigh backscattered light of pulsed lasers. Three Shack-Hartmann WFS are used to measure the wavefront distortion in the Ground Layer. The SLOpe Detection And Ranging (SLODAR) is a technique used to measure the atmospheric turbulence profiles. Cross correlation of wavefronts gradients from multiple stars are used to estimate the relative strength of turbulent layers at different altitudes. We present here the first results obteined on sky of appling the SLODAR technique to ARGOS comparing then with a previous study based on end-to-end simulations.

We present the first results of Argos, the multiple laser guide star and wavefront sensing facility for the Large Binocular Telescope. This system will deliver an improvement by a factor of two in FWHM over the 4′×4′ field of view of both Luci instruments. Luci 1 and Luci 2 are two near-infrared wide field imagers and multi-object spectrographs which capability and efficiency will be boosted by the increased resolution and encircled energy.The first on-sky ground-layer adaptive optics (GLAO) loop closure with Argos has been achieved in Fall 2014 on the right eye of the telescope. Stable operations in closed-loop have been demonstrated in May 2015 with hour-long integration and repeated good performances over several nights. Since then, the commissioning has been proceeding with the installation of the left system and the beginning of the left on-sky operations in this Fall 2015. The next achievements will be to strengthen the operational aspects and to perform science demonstration in both imaging and spectroscopic modes. We first present the current status of the project and review the operational aspects. Then, we analyze the first combined Luci and Argos observations and discuss the performances and the gains provided by Argos in term of scientific capabilities.

ARGOS is the laser guide star facility of the Large Binocular Telescope (LBT). It implements a Rayleigh Laser Guide Star system that provides Ground Layer Adaptive Optics (GLAO) correction for the LUCIs, the 2 wide- field near-infrared imagers and multi-object spectrographs installed on the 2 eyes of LBT. In this paper we describe how LBT’s adaptive optics operations have been tailored to ARGOS’s use cases based on the experience developed during over the ARGOS commissioning. We focus on all the aspects that are influenced by the use of the Laser Guide Stars, from collimation to acquisition and LGS guiding and we details the sequences to start, pause and resume the adaptive correction.

We aim to refine the sample of isolated early‐type galaxies in the Analysis of the interstellar Medium of Isolated Galaxies (AMIGA) catalog via high‐resolution imaging. Here, we report the result from a pilot study investigating two candidates, KIG 685 and KIG 895, in K‐band with the laser guide star and wavefront sensing facility ARGOS using the Large Binocular Telescope (LBT). Observations, obtained during the commissioning time, achieved a point spread function (PSF) of ≈0.25″. We present the data reduction and the PSF analysis from the best closed‐loop exposures to investigate the galaxies' morphological structure, including their nuclear region. We used PROFILER for the decomposition of the azimuthal 1D light distribution and GALFIT for the 2D analysis, accounting for ARGOS's PSF. KIG 685 was found to be a S0 galaxy and has been modeled with two Sérsic components representing a pseudobulge (n1D = 2.87 ± 0.21, n2D = 2.29 ± 0.10) and a disk (n1D = 0.95 ± 0.16, n2D = 0.78 ± 0.10). Nearly symmetric ring‐/shell‐like structures emerge after subtracting the GALFIT model from the image. KIG 895 shows a clear irregular arm‐like structure, in which the northern outer arm is reminiscent of a tail. The galaxy body is a disk, best fitted by a single Sérsic profile (n1D = 1.22 ± 0.1; n2D = 1.32 ± 0.12), that is, KIG 895 is a bulge‐less, very late‐type spiral. ARGOS high‐resolution images clearly showed interaction signatures in KIG 895. We suggest that the ring‐/shell‐like residuals in KIG 685, a bona fide early‐type galaxy, point toward a past accretion event. [ABSTRACT FROM AUTHOR]

Wedescribe an experiment where spin squeezing occurs spontaneously within a standard Ramsey sequence driving a two-component Bose--Einstein condensate (BEC) of87Rb atoms trapped in an elongated magnetic trap. The squeezing is generated by state-dependent collisional interactions, despite the near-identical scattering lengths of the spin states in 87Rb. In our proof-of-principle experiment, we observe a metrological spin squeezing that reaches 1.3 ± 0.4 dB for 5000 atoms, with a contrast of 90 ± 1%. The method may be applied to realize spin-squeezed BEC sources for atom interferometry without the need for cavities, state-dependent potentials or Feshbach resonances. [ABSTRACT FROM AUTHOR]