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The Adaptive Optics Facility (AOF) project envisages transforming one of the VLT units into an adaptive telescope and providing its ESO (European Southern Observatory) second generation instruments with turbulence corrected wavefronts. For MUSE and HAWK-I this correction will be achieved through the GALACSI and GRAAL AO modules working in conjunction with a 1170 actuators Deformable Secondary Mirror (DSM) and the new Laser Guide Star Facility (4LGSF). Multiple wavefront sensors will enable GLAO and LTAO capabilities, whose performance can greatly benefit from a knowledge about the stratification of the turbulence in the atmosphere. This work, totally based on end-to-end simulations, describes the validation tests conducted on a Cn2 profiler adapted for the AOF specifications. Because an absolute profile calibration is strongly dependent on a reliable knowledge of turbulence parameters r0 and L0, the tests presented here refer only to normalized output profiles. Uncertainties in the input parameters inherent to the code are tested as well as the profiler response to different turbulence distributions. It adopts a correction for the unseen turbulence, critical for the GRAAL mode, and highlights the effects of masking out parts of the corrected wavefront on the results. Simulations of data with typical turbulence profiles from Paranal were input to the profiler, showing that it is possible to identify reliably the input features for all the AOF modes., 15 pages, 12 figures, accepted for publication in the MNRAS Accepted 2015 January 22. Received 2015 January 21; in original form 2014 December 4

Two algorithms were recently studied for C 2 n profiling from wide-field Adaptive Optics (AO) measurements on GeMS (Gemini Multi-Conjugate AO system). They both rely on the Slope Detection and Ranging (SLODAR) approach, using spatial covariances of the measurements issued from various wavefront sensors. The first algorithm estimates the C 2 n profile by applying the truncated least-squares inverse of a matrix modeling the response of slopes covariances to various turbulent layer heights. In the second method, the profile is estimated by deconvolution of these spatial cross-covariances of slopes. We compare these methods in the new configuration of ESO Adaptive Optics Facility (AOF), a high-order multiple laser system under integration. For this, we use measurements simulated by the AO cluster of ESO. The impact of the measurement noise and of the outer scale of the atmospheric turbulence is analyzed. The important influence of the outer scale on the results leads to the development of a new step for outer scale fitting included in each algorithm. This increases the reliability and robustness of the turbulence strength and profile estimations.

The Gemini Multi-conjugate adaptive optics System (GeMS) at the Gemini South telescope in Cerro Pach{\'o}n is the first sodium-based multi-Laser Guide Star (LGS) adaptive optics system. It uses five LGSs and two deformable mirrors to measure and compensate for atmospheric distortions. The GeMS project started in 1999, and saw first light in 2011. It is now in regular operation, producing images close to the diffraction limit in the near infrared, with uniform quality over a field of view of two square arcminutes. The present paper (I) is the first one in a two-paper review of GeMS. It describes the system, explains why and how it was built, discusses the design choices and trade-offs, and presents the main issues encountered during the course of the project. Finally, we briefly present the results of the system first light., Comment: 17 pages, 7 figures, Accepted for publication in MNRAS

GeMS, the Gemini Laser Guide Star Multi-Conjugate Adaptive Optics facility system, has seen first light in December 2011, and has already produced images with H band Strehl ratio in excess of 35% over fields of view of 85x85 arcsec, fulfilling the MCAO promise. In this paper, we report on these early results, analyze trends in performance, and concentrate on key or novel aspects of the system, like centroid gain estimation, on-sky non­ common path aberration estimation. We also present the first astrometric analysis, showing very encouraging results.

It is a widely accepted conjecture that the width of the incoherent halo in an adaptive optics point-spread function (PSF) should decrease with the level of correction. Using end-to-end simulations we prove that this is not the case and the halo is actually increasing in width, albeit at a decreasing overall brightness level as must be the case with increasing correction. The simulations span the cases of: seeing-limited, partial-, and high-order adaptive-optics (AO) correction. We show the relationship between the theory of partially-developed speckle and the observed statistical behavior of on-axis PSF intensity. Finally, we check the results of the simulations with real data obtained using the 3.5m Starfire Optical Range telescope located in New Mexico, US. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

The effects of pupil motion on retinal imaging are studied in this paper. Involuntary eye or head movements are always present in the imaging procedure, decreasing the output quality and preventing a more detailed diagnostics. When the image acquisition is performed using an adaptive optics (AO) system, substantial gain is foreseen if pupil motion is accounted for. This can be achieved using a pupil tracker as the one developed by Imagine Eyes R®, which provides pupil position measurements at a 80Hz sampling rate. In any AO loop, there is inevitably a delay between the wavefront measurement and the correction applied to the deformable mirror, meaning that an optimal compensation requires prediction. We investigate several ways of predicting pupil movement, either by retaining the last value given by the pupil tracker, which is close to the optimal solution in the case of a pure random walk, or by performing position prediction thanks to auto-regressive (AR) models with parameters updated in real time. We show that a small improvement in prediction with respect to predicting with the latest measured value is obtained through adaptive AR modeling. We evaluate the wavefront errors obtained by computing the root mean square of the difference between a wavefront displaced by the assumed true position and the predicted one, as seen by the imaging system. The results confirm that pupil movements have to be compensated in order to minimize wavefront errors.

GeMS (the Gemini Multi-conjugated adaptive optics System) is a facility instrument for the Gemini-South telescope. It will deliver a uniform, diffraction-limited image quality at near-infrared (NIR) wavelengths over an extended FoV or more than 1 arcmin across. GeMS is a unique and challenging project from the technological point of view and because of its control complexity. The system includes 5 laser guide stars, 3 natural guide stars, 3 deformable mirrors optically conjugated at 0, 4.5 and 9km and 1 tip-tilt mirror. After 10 years since the beginning of the project, GeMS is finally reaching a state in which all the subsystems have been received, integrated and, in the large part, tested. In this paper, we report on the progress and current status of the different sub-systems with a particular emphasis on the calibrations, control and optimization of the AO bench.

We perform simulations of a single-conjugated adaptive optics (SCAO) system for an E-ELT-like telescopeusing a pyramid wavefront sensor (PWFS) and an on-axis NGS. The advantage of this WFS has already beendemonstrated, being currently preferred in many AO syste ms where high signal sensitivity is critical. The mainobjective of this work is to evaluate the performance of such SCAO system under dierent control parameters(loop gain, modulation, truncated SVD mode), sensing wavelengths, atmospheric coherence scales and NGSmagnitudes. Always adopting K as the science band, we have veri“ed that the overall performance tends tobe poorer as the sensing wavelength becomes shorter. The loop gain optimal range is dependent on the SVDtruncation threshold used to build the command matrix, and a non-modulated PWFS produces in general poorerresults when compared to modulated cases, being this especially true for the R- sensing band. The defaultatmospheric model adopted was a von Karman with r

Modeling adaptive optics (AO) systems is crucial to understanding their performance and a key aid in their design. The Giant Magellan Telescope (GMT) is planning three AO modes at first light: natural guide star AO, ground-layer AO and laser tomography AO. This paper describes how a modified version of YAO, an open-source general-purpose AO simulation tool written in Yorick, is used to simulate the GMT AO modes. The simulation tool was used to determine the piston segment error for the GMT. In addition, we present a comparison of different turbulence simulation approaches.

The Laser Adaptive Optics system of the 6.5 m MMT telescope has now been commissioned with Ground Layer Adaptive Optics operations as a tool for astronomical science. In this mode the wavefronts sampled by each of five laser beacons are averaged, leading to an estimate of the aberration in the ground layer. The ground layer is then compensated by the deformable secondary mirror at 400 Hz. Image quality of 0.2-0.3 arc sec is delivered in the near infrared bands from 1.2-2.5 μm over a field of view of 2 arc minutes. Tomographic wavefront sensing tests in May 2010 produced open loop data necessary to streamline the software to generate a Laser Tomography Adaptive Optics (LTAO) reconstructor. In addition, we present the work being done to achieve optimal control PID wavefront control and thus increase the disturbance rejection frequency response for the system. Finally, we briefly describe plans to mount the ARIES near infrared imager and echelle spectrograph, which will support the 2 arc min ground-layer corrected field and will exploit the diffraction limit anticipated with LTAO.

The final phase of implementation of all optical components, as well as their integration and tests on the Canopus MCAO bench is currently underway. We present here a detailed description of the LGS and NGS WFS calibration sequences implemented through MYST (MCAO Y orick Smart Tool), a yorick+python+glade software package developed in-house which allows multiple users to control and monitor the bench remotely over the network using EPICS b commands. A fine tuning of the optical setup and a better under standing of the flexure /temperature dependencies is being carried out and will allow us to build the many look-up tables to be eventually used by the system (e.g. telescope primary and secondary mirrors). Preliminary work on non-common path aberrations to account for the static aberrations in th e central 60 arcsec science field of view (FoV) has been done iteratively using a science focal plane wavefront sensor and has shown good results both in individual directions as well as simultaneously over the entire FoV, the latter using the tomographic approach (presented in another paper in this conference).

The Gemini MCAO system, GeMS, is currently undergoing integration and test at the Gemini South base facility. GeMS has been in the work since 2001, and is finally reaching a state in which all the subsystems, except for the 50W laser, have been received, integrated and, in the large part, tested. In this paper, after a brief description of the system, we describe selected methods and results that we have obtained during the on-going integration period.

The Gemini Multi-conjugate adaptive optics System (GeMS) is a facility instrument for the Gemini- South telescope that can provide near-uniform atmospheric compensation over a 1 arc minute square field of view. To provide di raction-limited image quality at near IR wavelengths across an extended field-of-view, the system includes 5 laser guide stars, 3 natural guide stars and 3 deformable mirrors optically conjugated at 0, 4.5 and 9km. By many ways, GeMS represents a unique system to prepare and understand any future wide field AO systems planned for the ELTs. In this paper, we present the di erent strategies developed for the phase volume estimation and correction relative to the LGS high-order path. We compare the performance obtained by a Least-Square Estimator (LSE) and a Minimum Mean Square Error (MMSE) reconstructor. The MMSE reconstructor is found to improve the performance compared to the classical LSE, particularly when the system is a ected by noise. We show the results obtained by realistic simulations as well as the first results obtained in laboratory on CANOPUS, the GeMS AO bench.

We show the performance derived from simulations of a single-conjugated adaptive optics (SCAO) system for an ELT using the pyramid wavefront sensor (hereafter PWFS). The main objective of this work is to obtain the parameters which optimize the Strehl and characterize the system. Adopting K as the science band, we verify that the overall performance tends to be poorer as the sensing wavelength becomes shorter (as we probed K, J and R bands), the loop gain optimal range is dependent on the singular-value decomposition (SVD) truncation threshold used to build the command matrix, and that a "natural" modulation for the PWFS (i.e. zero modulation) produces in general poorer results when compared to modulated cases, being this especially true for the R-sensing band. Also more modulation is needed as one goes to shorter wavelengths. Comparisons between a scaled-down version of the simulations and those for a 42m telescope are performed. The atmospheric model adopted was always a von Karman with r0=0.13m@500nm and outer-scale L0=25m. The telescope pupil had a central obstruction of 28% and no spiders. The NGS was put on-axis, and di raction between pyramid imaged pupils taken into account.

This paper studies the effect of pupil displacements on the best achievable performance of retinal imaging adaptive optics (AO) systems, using 52 trajectories of horizontal and vertical displacements sampled at 80 Hz by a pupil tracker (PT) device on 13 different subjects. This effect is quantified in the form of minimal root mean square (rms) of the residual phase affecting image formation, as a function of the delay between PT measurement and wavefront correction. It is shown that simple dynamic models identified from data can be used to predict horizontal and vertical pupil displacements with greater accuracy (in terms of average rms) over short-term time horizons. The potential impact of these improvements on residual wavefront rms is investigated. These results allow to quantify the part of disturbances corrected by retinal imaging systems that are caused by relative displacements of an otherwise fixed or slowy-varying subject-dependent aberration. They also suggest that prediction has a limited impact on wavefront rms and that taking into account PT measurements in real time improves the performance of AO retinal imaging systems.

We present a spectroscopic atlas of active galactic nuclei covering the region around the 8498, 8542, 8662 Calcium triplet (CaT) lines. The sample comprises 78 objects, divided into 43 Seyfert 2s, 26 Seyfert 1s, 3 Starburst and 6 normal galaxies. The spectra pertain to the inner ~300 pc in radius, and thus sample the central kinematics and stellar populations of active galaxies. The data are used to measure stellar velocity dispersions (sigma_star) both with cross-correlation and direct fitting methods. These measurements are found to be in good agreement with each-other and with those in previous studies for objects in common. The CaT equivalent width is also measured. We find average values and sample dispersions of W_CaT of 4.6+/-2.0, 7.0 and 7.7+/-1.0 angstrons for Seyfert 1s, Seyfert 2s and normal galaxies, respectively. We further present an atlas of [SIII]\lambda 9069 emission line profiles for a subset of 40 galaxies. These data are analyzed in a companion paper which addresses the connection between stellar and Narrow Line Region kinematics, the behaviour of the CaT equivalent width as a function of sigma_star, activity type and stellar population properties., Comment: 18 pages, 10 figures, accepted for publication in MNRAS

NGC 7582 is defined as a Starburst/AGN galaxy, since its optical and X-Ray spectra reveal both characteristics. In this work, we show the results of a stellar population modeling in a datacube taken with the Gemini South telescope. We found that $\sim$ 90% of the light in the field of view is emitted by stars that are less than 1 billion years old. A strong burst occurred about $\sim$ 6 million years ago and has nearly solar metallicity. We also found a Wolf-Rayet cluster., Comment: 2 pages, 2 figures, to be published in the Proceedings of the IAU Symposium no. 262

Fe ii comprises up to one third of the line emission in AGNs. For that reason it is an important coolant that needs to be taken into account to fully understand the energetics of the broad line region (BLR). As such, Fe+ is a potential diagnostic of gas density, column density, turbulence, temperature and continuum shape. However, understanding Fe ii is complicated because of the energy level configuration and different mechanisms that may contribute to the line emission.