Andrea La Camera

Spatially resolved m-band emission from io's Loki Patera-fizeau imaging at the 22.8 m LBT

The Large Binocular Telescope Interferometer mid-infrared camera, LMIRcam, imaged Io on the night of 2013 December 24 UT and detected strong M-band (4.8 μm) thermal emission arising from Loki Patera. The 22.8 m baseline of the Large Binocular Telescope provides an angular resolution of ∼32 mas (∼100 km at Io) resolving the Loki Patera emission into two distinct maxima originating from different regions within Loki’s horseshoe lava lake. This observation is consistent with the presence of a high-temperature source observed in previous studies combined with an independent peak arising from cooling crust from recent resurfacing. The deconvolved images also reveal 15 other emission sites on the visible hemisphere of Io including two previously unidentified hot spots.

The CAOS problem-solving environment: recent developments

We present recent developments of the CAOS problem-solving environment (PSE), an IDL-based software tool whose original aim was to define and simulate as realistically as possible the behavior of a generic adaptive optics (AO) system -from the atmospheric propagation of light, to the sensing of the wave-front aberrations and the correction through a deformable mirror- but which results in a widely more general tool now. In fact, the different developments made through the last years result in a very versatile numerical tool complete of a global graphical interface (the CAOS Application Builder), a general utilities library (the CAOS Library), and different packages dedicated to a wide range of astronomical-optics-related scientific topics: the original package designed for end-to-end AO system simulations (the Software Package CAOS), an image simulation/ reconstruction package with interferometric capabilities (the Software Package AIRY), an extension of the latter specialized for the LBT instrument LINC-NIRVANA (the Software Package AIRY-LN), an ad hoc package dedicated to the VLT instrument SPHERE (the Software Package SPHERE), and an embedment of the analytical AO simulation code PAOLA (the Software Package PAOLAC).We present the status of the whole CAOS PSE, together with the most recent developments, and plans for the future of the overall tool.

Image reconstruction for observations with a high dynamic range: LINC-NIRVANA simulations of a stellar jet

We report the results of a simulation and reconstruction of observations of a young stellar object (YSO) jet with the LINC-NIRVANA (LN) interferometric instrument, which will be mounted on the Large Binocular Telescope (LBT). This simulation has been performed in order to investigate the ability of observing the weak diffuse jet line emission against the strong IR stellar continuum through narrow band images in the H and K atmospheric windows. In general, this simulation provides clues on the image quality that could be achieved in observations with a high dynamic range. In these cases, standard deconvolution methods, such as Richardson-Lucy, do not provide satisfactory results: we therefore propose here a new method of image reconstruction. It consists in considering the image to be reconstructed as the sum of two terms: one corresponding to the star (whose position is assumed to be known) and the other to the jet. A regularization term is introduced for this second component and the reconstruction is obtained with an iterative method alternating between the two components. An analysis of the results shows that the image quality obtainable with this method is significantly improved with respect to standard deconvolution methods, reducing the number of artifacts and allowing us to reconstruct the original jet intensity distribution with an error smaller than 10%.

Analysis of LBT LINC-NIRVANA simulated images of galaxies and young stellar objects

LINC-NIRVANA (LN) is a Fizeau interferometer that will provide for the first time coherent images in the near-IR combining the beams from the two Large Binocular Telescope (LBT)arms, by adopting a Multi-Coniugate Adaptive Optics system (MCAO) that allows for atmospheric turbulence compensation. We applied a software for the simulation and the reconstruction of LN images (AIRY-LN, see Desidera et al.1 this Conference) in two specific scientific cases: a relatively distant galaxy at redshift about 1 and a collimated jet from a Young Stellar Object (YSO). These two cases have been chosen to test the capability of LN in the observations of faint and small (1-2 arcsec) extragalactic objects and objects with diffuse emission and high dynamical range, respectively. A total of six images at different hour angles have been obtained for both cases. Using these simulated images, we obtained the final reconstructed images using the software package AIRY-LN. These images have been analyzed with the standard data reduction software (IRAF and IDL). Our analysis show that the reconstruction algorithm is fundamental to obtain a good reproduction of the original flux and morphology while the optimal number of iterations strongly depends on the scientific goal.

AIRY: a complete tool for the simulation and the reconstruction of astronomical images

The Software Package AIRY (acronym for Astronomical Image Restoration in interferometrY) is a software tool designed to perform simulation and/or deconvolution of images of Fizeau interferometers as well as of any kind of optical telescopes. AIRY is written in IDL and is a Software Package of the CADS Problem Solving Environment (PSE): it is made of a set of modules, each one representing a specific task. We present here the last version of the software, arrived at its sixth release after 10 years of development. This version of AIRY summarizes the work done in recent years by our group, both on AIRY and on AIRY-LN, the version of the software dedicated to the image restoration of LINC-NIRVANA (LN), the Fizeau interferometer of the Large Binocular Telescope (LBT). AIRY v.6.0 includes a renewed deconvolution module implementing regularizations, accelerations, and stopping criteria of standard algorithms, such as OSEM and Richardson-Lucy. Several modules of AIRY have been improved and, in particular, the one used for the extraction and extrapolatioThe Software Package AIRY (acronym for Astronomical Image Restoration in interferometrY) is a software tool designed to perform simulation and/or deconvolution of images of Fizeau interferometers as well as of any kind of optical telescopes. AIRY is written in IDL and is a Software Package of the CAOS Problem Solving Environment (PSE): it is made of a set of modules, each one representing a speci_c task. We present here the last version of the software, arrived at its sixth release after 10 years of development. This version of AIRY summarizes the work done in recent years by our group, both on AIRY and on AIRY-LN, the version of the software dedicated to the image restoration of LINC-NIRVANA (LN), the Fizeau interferometer of the Large Binocular Telescope (LBT). AIRY v.6.0 includes a renewed deconvolution module implementing regularizations, accelerations, and stopping criteria of standard algorithms, such as OSEM and Richardson-Lucy. Several modules of AIRY have been improved and, in particular, the one used for the extraction and extrapolation of the PSF. In addition, AIRY has modules dedicated to the simulation of interferometric images and utility modules for data reading, writing, and visualization. After a description of the implemented reconstruction methods and of the whole set of modules, we provide several example projects in order to give to the astronomical community a powerful tool for the preparation of the observations and for the real data deconvolution.n of the PSF. In addition, AIRY has modules dedicated to the simulation of interferometric images and utility modules for data reading, writing, and visualization. After a description of the implemented reconstruction methods and of the whole set of modules, we provide several example projects in order to give to the astronomical community a powerful tool for the preparation of the observations and for the real data deconvolution.

LINC-NIRVANA for the large binocular telescope: setting up the world’s largest near infrared binoculars for astronomy

LINC-NIRVANA (LN) is the near-infrared, Fizeau-type imaging interferometer for the large binocular telescope (LBT) on Mt. Graham, Arizona (elevation of 3267 m). The instrument is currently being built by a consortium of German and Italian institutes under the leadership of the Max Planck Institute for Astronomy in Heidelberg, Germany. It will combine the radiation from both 8.4 m primary mirrors of LBT in such a way that the sensitivity of a 11.9 m telescope and the spatial resolution of a 22.8 m telescope will be obtained within a 10.5×10.5 arcsec 2 scientific field of view. Interferometric fringes of the combined beams are tracked in an oval field with diameters of 1 and 1.5 arcmin. In addition, both incoming beams are individually corrected by LN’s multiconjugate adaptive optics system to reduce atmospheric image distortion over a circular field of up to 6 arcmin in diameter. A comprehensive technical overview of the instrument is presented, comprising the detailed design of LN’s four major systems for interferometric imaging and fringe tracking, both in the near infrared range of 1 to 2.4 μm, as well as atmospheric turbulence correction at two altitudes, both in the visible range of 0.6 to 0.9 μm. The resulting performance capabilities and a short outlook of some of the major science goals will be presented. In addition, the roadmap for the related assembly, integration, and verification process are discussed. To avoid late interface-related risks, strategies for early hardware as well as software interactions with the telescope have been elaborated. The goal is to ship LN to the LBT in 2014.

Analysis of LBT LINC-NIRVANA simulated images of galaxies

LINC-NIRVANA (LN) is a Fizeau interferometer that will provide coherent images in the near-IR combining the beams from the two Large Binocular Telescope (LBT) arms, by adopting a Multi-Conjugate Adaptive Optics system (MCAO) that allows for atmospheric turbulence compensation. We applied the software AIRY-LN for the simulation and the reconstruction of LN images in order to investigate the dependence of the image quality from the magnitude of the star used for the PSF extraction. A good knowledge of this dependence is a crucial point for the LN observations, especially for the extragalactic target where the presence of a bright psf-star within the LN field of view of 10×10 arcsec is not granted. Our results, although still preliminary, show that while from the morphological point of view the use of psf-star up to a magnitude of 18 is still acceptable, from the photometric point of view the use of psf-star fainter than Ks ~ 16 mag could cause considerable problems.

Image restoration with spatially variable PSF

We present a method for the restoration of astronomical images obtained with Adaptive Optics (AO) systems. In order to maximize the scientific return from AO data and, in general, from the data of the next generation telescopes, we developed a restoration method based on deconvolution for the de-blurring of images degraded by a spatially variable PSF. The deconvolution method is based on a partition of the image domain in partially overlapping sub-domains where the PSF can be assumed to be space invariant. The software, called Patch, is written in IDL language and is freely distributed to the community. Here we report a general description of the method and of its graphical interface. The potentiality of the Software Patch have been tested on two completely different astrophysical scenarios: a crowded stellar field and an extended galaxy. Despite the very conservative assumptions made on the Point Spread Function (assumed to be strongly variable across the field of view), we obtained good results in terms of image reconstruction both for the stellar (point-like) case and for the extended galaxy.

Strehl-constrained reconstruction of post-adaptive optics data and the Software Package AIRY, v. 6.1

We first briefly present the last version of the Software Package AIRY, version 6.1, a CAOS-based tool which includes various deconvolution methods, accelerations, regularizations, super-resolution, boundary effects reduction, point-spread function extraction/extrapolation, stopping rules, and constraints in the case of iterative blind deconvolution (IBD). Then, we focus on a new formulation of our Strehl-constrained IBD, here quantitatively compared to the original formulation for simulated near-infrared data of an 8-m class telescope equipped with adaptive optics (AO), showing their equivalence. Next, we extend the application of the original method to the visible domain with simulated data of an AO-equipped 1.5-m telescope, testing also the robustness of the method with respect to the Strehl ratio estimation.

The CAOS Problem-Solving Environment: tools for AO numerical modeling and post-AO deconvolution

The CAOS problem-solving environment (PSE) is an IDL-based tool developed for adaptive optics (AO) modeling and post-AO imaging. Two scientific packages enhance the CAOS PSE: the Software Package AIRY, a tool for deconvolution of post-AO images, and the eponymous Software Package CAOS, an end-to-end code for AO system simulations. In the first part of this paper we present the status and most recent developments concerning the whole CAOS PSE and its two presently developed scientific packages, while in the rest of the paper we provide two examples of application involving the Software Package AIRY: one tackling high-dynamic range images reconstruction, and the other one real data processing.