Found 19 talks width keyword adaptive optics
Abstract
In collaboration with member states institutes, the use of the synergies with ESO is producing first important results in the R&D for Laser Guide Star adaptive optics, to be used for the large and extremely large telescope projects.
In this talk we will report on the preliminary results of the current campaign on LGS return flux with laser guide stars at Observatorio de el Teide and the foreseen tests of the EELT LGS-AO scheme, to be done at the WHT starting in summer 2016. An outlook will be given on the proposal for further feasibility tests at WHT in 2018-19, to experiment novel LGS-AO schemes using uplink beam correction and pyramid wavefront sensing. The demonstration is for a LGS-AO scheme giving high Strehl on the EELT and adaptive optics in the visible on 8m class telescopes.
Abstract
In the past years, intensive Site Characterization campaigns have been performed to chose the sites for the future giant ELTs. Various atmospheric turbulence profilers with different resolution and sensed altitude ranges have been used, as well as climatological tools and satellite data analysis. Mixing long term statistics at low altitude resolution with high resolution data collected during short term campaigns allows to produce the reference profiles as input to the Adaptive Optics (AO) instrument performance estimators. In this talk I will perform a brief review of the principal and most used instruments and tools in order to give to the audience a panorama of the work and the efforts to monitor the atmospheric turbulence for astronomical purposes.
Abstract
Adaptive optics systems rely on a real-time control system which is responsible for receiving wavefront sensor information and computing and applying the necessary correction to the deformable mirrors. Historically, real-time control systems have relied on customised hardware comprised of multiple FPGA and DSP systems, which high complexity. More recently it has been demonstrated that conventional PCs are now sufficiently powerful to to perform this task. In this talk, I will present an open-source real-time control system, DARC, discuss its implementation on the CANARY AO system at the William Herschel Telescope, and cover the algorithms available. Extension to ELT-scale operation will be discussed, including hardware and detector considerations. The internal architecture of this modular system will be presented, with a case being made for its suitability for implementation on any AO system type, on any telescope.
Abstract
One of the challenges in solar astronomical observations is the lack of high resolution observations over a wide FOV. Adaptive optics (AO) systems, which are routinely used in current solar telescopes, can only provide successful correction over a narrow FOV. Multi-conjugate adaptive optics (MCAO) systems attempt to address this issue and provide correction over a much wider FOV. It will become a key technology in the next generation of solar telescopes, such as the EST and DKIST. At this time, there is no fully operational solar MCAO system in operation. Work is under way at several solar facilities like the NST (Ø1.6m, BBSO) and GREGOR (Ø1.5m, KIS) to build prototype solar MCAO
systems. There is also a significant investigative effort at the IAC to study the design and operation of a solar MCAO system (proper location of the DMs and WFS, appropriated sensing for an extended object,
communication between different WFS, convenient reconstruction method). This talk will provide a review of the current state of solar MCAO, concentrating on solar MCAO simulation efforts under development
at the National Solar Observatory.
Abstract
ESO is an intergovernmental organization for astronomy founded in 1962 by five countries. It currently has 14 Member States in Europe with Brazil poised to join as soon as the Accession Agreement has been ratified. Together these countries represent approximately 30 percent of the world’s astronomers. ESO operates optical/infrared observatories on La Silla and Paranal in Chile, partners in the sub-millimeter radio observatories APEX and ALMA on Chajnantor and is about to start construction of the Extremely Large Telescope on Armazones.
La Silla hosts various robotic telescopes and experiments as well as the NTT and the venerable 3.6m telescope. The former had a key role in the discovery of the accelerating expansion of the Universe and the latter hosts the ultra-stable spectrograph HARPS which is responsible for the discovery of nearly two-thirds of all confirmed exoplanets with masses below that of Neptune. On Paranal the four 8.2m units of the Very Large Telescope, the Interferometer and the survey telescopes VISTA and VST together constitute an integrated system which supports 16 powerful facility instruments, including adaptive-optics-assisted imagers and integral-field spectrographs, with half a dozen more on the way and the Extremely Large Telescope with its suite of instruments to be added to this system in about ten years time. Scientific highlights include the characterisation of the supermassive black hole in the Galactic Centre, the first image of an exoplanet, studies of gamma-ray bursts enabled by the Rapid Response Mode and milliarcsec imaging of evolved stars and active galactic nuclei. The single dish APEX antenna, equipped with spectrometers and wide-field cameras, contributes strongly to the study of high-redshift galaxies and of star- and planet-formation. Early Science results obtained with the ALMA interferometer already demonstrate its tremendous potential for observations of the cold Universe.
Abstract
CANARY is a technical demonstrator for the proposed EAGLE instrument for European ELT. EAGLE will have twenty Integral Field Units patrolling a 5 arcminute field and requires a new form of adaptive optics to provide the required image quality for its 0.0375 arcsec image sampling: Laser Guide Star Multi-Object AO. This entails several significant technical innovations: open-loop control, atmospheric tomography, and new calibration methods. The CANARY demonstrator is currently in its first, natural guide star, phase, and the first results have been obtained on sky. CANARY Phase A is described and the first results are presented. The next, laser guide star, phase is then outlined.
Abstract
I will present a short introduction to speckle imaging and the so-called speckle holography technique. Subsequently, I will present results of speckle observations with the VLT (NACO) and Keck (NIRC) telescopes. The experiments demonstrate that in the observed targets speckle imaging combined with holographic image reconstruction provides imaging quality that can compete with and even supersede current adaptive optics (AO) imaging systems. Speckle imaging is a way to achieve reliable, high-quality, diffraction limited imaging capacity at relatively low costs. I will discuss what would be the estimated performance of speckle cameras at the WHT and GTC and sketch possible concepts.Abstract
The ambitious astrophysical objectives of the Extremely Large Telescopes (ELTs) will be achievable only with innovative Adaptive Optics (AO) systems to correct for the wavefront distortions induced by the turbulence in the atmosphere. One of the key components of an AO system is the wavefront reconstruction, which is a real-time estimate of the wavefront distortions above the telescope aperture from data. This reconstruction can be described by an inverse problem approach (IPA),taking advantage of the modeling of second-order statistics of both turbulence and data noise.First, the benefits of the IPA to wavefront reconstruction is enhanced for two particularities of the ELTs: very high number of estimated parameters (~104) and elongated spots on the sensor for AO using Laser Guide Stars. Moreover, this IPA can be implemented with a fast algorithm for high number of degrees of freedom, which makes it a candidate for the implementation on a future AO system of the E-ELT. The correction performance in closed-loop AO has also been assessed thanks to end-to-end simulations of single-conjugate AO and Ground-Layer AO with Laser Guide Stars on the E-ELT.
Abstract
Starbursts and AGNs are frequently coupled in the central kiloparsecs of Seyfert galaxies, where molecular gas plays a critical role in fueling nuclear starburst activity and feeding the central black hole. Unveiling the dusty nuclear regions with high-spatial resolution techniques in the near-infrared (NIR) permits us to disentangle the AGN and the stellar clusters, characterizing both sources separately. In this context, a small sample of nearby galaxies have been observed with VLT/NaCo adaptive optics in the NIR. These observations were completed with similar high-spatial resolution data in the mid-infrared (VLT/VISIR), optical (HST) and radio wavelengths (VLA). A new alignment for the starburst galaxy NGC 253 was found based on NIR and radio data, due to the high-spatial resolution in both spectral regions, finding NIR counterparts for 8 known radio sources. It is remarkable the lack of any optical or IR counterpart for the radio core, proposed as a low luminosity AGN, which presents an IR-to-radio emission ratio similar (or even lower) than Sgr. A*. Using the high-spatial resolution aligned dataset from optical-IR to radio wavelengths we derived a representative spectral energy distribution (SED) based on 37 young dust embedded clusters resolved in the inner 0.4 kpc. The template is characterized by a maximum at 20 μ and a gentle bump in the 1-2 μ range. These features, absent in lower spatial resolution templates, can be well reproduced by considering an important contribution of very young stellar objects to the IR, and are thus associated with hot dust surrounding the protostars. The average SED was then compared with the nuclear star forming regions found in the Seyfert 2/starburst galaxy NGC 7582.<< First « Newer 1 | 2 Older »
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