Johann Kolb
A5015023164- Adaptive optics and wavefront sensing
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Advanced optical system design
- Optical Systems and Laser Technology
- Optical Wireless Communication Technologies
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Infrared Target Detection Methodologies
- Calibration and Measurement Techniques
- Advanced Measurement and Metrology Techniques
- Optical measurement and interference techniques
- Magnetic Properties and Applications
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Model Reduction and Neural Networks
- Wireless Power Transfer Systems
- Astrophysics and Cosmic Phenomena
- Electric Motor Design and Analysis
- Advanced Fiber Optic Sensors
- Magnetic Bearings and Levitation Dynamics
- Building Energy and Comfort Optimization
European Southern Observatory
2010-2024
RWTH Aachen University
2019-2023
European Southern Observatory
2017-2020
Max Planck Society
2018
University of Rostock
2018
Siemens (United States)
2014
GRAVITY is a new instrument to coherently combine the light of European Southern Observatory Very Large Telescope Interferometer form telescope with an equivalent 130 m diameter angular resolution and collecting area 200 m$^2$. The comprises fiber fed integrated optics beam combination, high spectroscopy, built-in analysis control, near-infrared wavefront sensing, phase-tracking, dual operation laser metrology [...]. This article gives overview reports on performance first astronomical...
Tight relationships exist in the local universe between central stellar properties of galaxies and mass their supermassive black hole. These suggest holes co-evolve, with main regulation mechanism being energetic feedback from accretion onto hole during its quasar phase. A crucial question is how relationship evolves time; a key epoch to probe this at peaks star formation growth 8-12 billion years ago (redshifts 1-3). Here we report dynamical measurement luminous redshift 2, look back time...
Giant exoplanets on wide orbits have been directly imaged around young stars. If the thermal background in mid-infrared can be mitigated, then with lower masses also imaged. Here we present a ground-based observing approach that enables imaging low-mass temperate nearby stars, and particular within closest stellar system, α Centauri. Based 75-80% of best quality images from 100 h cumulative observations, demonstrate sensitivity to warm sub-Neptune-sized planets throughout much habitable zone...
GALACSI is one of the Adaptive Optics (AO) systems part ESO Facility (AOF). It will use VLT 4-Laser Guide Stars system, high speed and low noise WaveFront Sensor cameras (<1e-, 1000Hz) Deformable Secondary Mirror (DSM) SPARTA Real Time Computer to sharpen images enhance faint object detectability MUSE Instrument. an Integral Field Spectrograph working at wavelengths from 465nm 930nm. implements 2 different AO modes; in Wide Mode (WFM) it perform Ground Layer correction collected energy a...
Context. Here we describe a simple, efficient, and most importantly fully operational point-spread-function (PSF)-reconstruction approach for laser-assisted ground layer adaptive optics (GLAO) in the frame of Multi Unit Spectroscopic Explorer (MUSE) wide field mode. Aims. Based on clear astrophysical requirements derived by MUSE team using functionality current ESO Adaptive Optics Facility aim to develop an PSF-reconstruction (PSFR) algorithm test it both simulations on-sky data. Methods....
Context. Deep photometry of crowded fields, such as Galactic globular clusters, is severely limited by the resolution ground-based telescopes. On other hand, Hubble Space Telescope does not have near-infrared (NIR) filters needed to allow large color baselines.
Context. The tip-tilt stabilisation system of the 1.8 m Auxiliary Telescopes Very Large Telescope Interferometer was never dimensioned for robust fringe tracking, except when atmospheric seeing conditions are excellent. Aims. Increasing level wavefront correction at telescopes is expected to improve coupling into single-mode fibres instruments, and enable tracking even in degraded conditions. Methods. We deployed a new adaptive optics module interferometry (NAOMI) on Telescopes. Results....
Context. The GRAVITY+ upgrade implies a complete renewal of its adaptive optics (AO) systems. Its complex design, featuring moving components between the deformable mirrors and wavefront sensors, requires monitoring auto-calibrating lateral mis-registrations system while in operation. Aims. For preset target acquisition, large registration errors must be assessed open loop to bring state where AO closes. In closed loop, these monitored corrected, without impacting science. Methods. With...
Nearby young clusters are privileged places to study the star formation history. Over last decade, sigma-Orionis cluster has been a prime location for of very low mass stars, substellar and isolated planetary objects determination initial function. To extend previous studies this association its core, we searched ultracool members new multiple systems within 1.5'x1.5' central region cluster. We obtained deep multi-conjugate adaptive optics (MCAO) images core with prototype MCAO facility MAD...
The Deformable Secondary Mirror (DSM) for the VLT ended stand-alone electro-mechanical and optical acceptance process, entering test phase as part of Adaptive Optics Facility (AOF) at ESO Headquarter (Garching). VLT-DSM currently represents most advanced already-built large-format deformable mirror with its 1170 voice-coil actuators internal metrology based on co-located capacitive sensors to control shape 1.12m-diameter 2mm-thick convex shell. present paper reports final results...
Background. The analysis of volatile organic compounds (VOCs) in breath allows non-invasive investigations diseases. Animal studies are conducted as a model to perform research VOCs and their relation In large animal models ruminants were often used experimental targets. effect physiological eructation on VOC exhalation has not been examined yet is the objective this study. Methods. Continuous profiles two young cattle, four adult goats sheep measured through mask, covering mouth nose,...
The Multi-Conjugate Adaptive Optics Demonstrator (MAD) built by ESO with the contribution of two external consortia is a powerful test bench for proving feasibility (MCAO) and Ground Layer (GLAO) techniques both in laboratory on sky. MAD based deformable mirrors correction system multi-reference wavefront sensors (Star Oriented Oriented) capable to observe simultaneously some pre-selected configurations Natural Guide Stars. corrects up 2 arcmin field view K band. After long phase, it has...
The estimation of atmospheric turbulence parameters is relevance for: a) site evaluation & characterisation; b) prediction the point spread function; c) live assessment error budgets and optimisation adaptive optics performance; d) fringe trackers for long baseline optical interferometry. ubiquitous deployment Shack-Hartmann wavefront sensors in large telescopes makes them central parameter via telemetry. Several methods Fried outer scale have been developed, most which are based on fitting...
The Adaptive Optics Facility is an ESO project aiming at converting Yepun, one of the four 8m telescopes in Paranal, into adaptive telescope. This done by replacing current conventional secondary mirror Yepun a Deformable Secondary Mirror (DSM) and attaching Laser Guide Star (LGS) Units to its centerpiece. In meantime, two (AO) modules have been developed incorporating each LGS WaveFront Sensors (WFS) tip-tilt sensor used control DSM 1 kHz frame rate. AO module (GRAAL) already assembled on...
In this article the sensitivity of manufacturing tolerances on output a permanent magnet synchronous machine with stator segmentation is studied. To reduce simulation effort, transition segment air gaps to replacement geometry was applied and relevant parameters are discussed, whereas uncertainty geometric material modeled normal distribution. Furthermore, tolerance chains expressed through convolution independent probability distributions. For Design Experiments Sobol sequences utilized....
Several designs of future Adaptive Optics (AO) systems propose to use a large Deformable Mirror (DM), regarding the size as well number actuators. Most time, there is no focal plane upstream DM. Therefore, classical way calibrating interaction matrix on an artificial source cannot be applied. Furthermore, requirements in terms calibration error budget are tight and high order modes such DMs stiff hence they achieve only small stroke. This why novel ways determine system Interaction Matrix...
Context.Multi-conjugate adaptive optics (MCAO) combine the advantages of both standard optics, which provide high contrast and spatial resolution, wide field imaging (≈1'). Up to recently, MCAO for astronomy was limited laboratory experiments. In this paper, we present first scientific results obtained with instrument.
BL Lac objects are low--power active nuclei exhibiting a variety of peculiar properties that caused by the presence relativistic jet and orientation effects. We present here adaptive optics near-IR images at high spatial resolution nearby object PKS 0521-365, which is known to display prominent both radio optical frequencies. The observations were obtained in Ks--band using ESO multi-conjugated demonstrator Very Large Telescope. This allowed us obtain with 0.1 arcsec effective resolution....
The Adaptive Optics Facility project is completing the integration of its systems at ESO Headquarters in Garching. main test bench ASSIST and 2<sup>nd</sup> Generation M2-Unit (hosting Deformable Secondary Mirror) have been granted acceptance late 2012. DSM has undergone a series tests on 2013 which validated optical performance launched System Test Phase AOF. This followed by evaluation GRAAL natural guide star mode on-axis will continue 2014 with Ground Layer AO mode. GALACSI module (for...
For two years starting in February 2014, the AO modules GRAAL for HAWK-I and GALACSI MUSE of Adaptive Optics Facility project have undergone System Testing at ESO's Headquarters. They offer four different modes: NGS SCAO, LGS GLAO IR, LTAO visible. A detailed characterization those modes was made possible by existence ASSIST, a test bench emulating an adaptive VLT including Deformable Secondary Mirror, star simulator turbulence generator focal plane re-imager. This phase aimed validating all...
GALACSI is the Adaptive Optics (AO) module that will serve MUSE Integral Field Spectrograph. In Wide Mode it enhance collected energy in a 0.2"×0.2" pixel by factor 2 at 750 nm over of View (FoV) 1'×1' using Ground Layer AO (GLAO) technique. Narrow Mode, provide Strehl Ratio 5% (goal 10%) 650 nm, but smaller FoV (7.5"×7.5" FoV), Laser Tomography (LTAO). Before being ready for shipping to Paranal, system has gone through an extensive testing phase Europe, first standalone mode and then closed...
The success of the next generation instruments for ELT class telescopes will depend upon improving image quality by exploiting sophisticated Adaptive Optics (AO) systems. One critical components AO systems E-ELT has been identified as optical Laser/Natural Guide Star WFS detector. combination large format, 1760×1680 pixels to finely sample wavefront and spot elongation laser guide stars, fast frame rate 700 frames per second (fps), low read noise (< 3e-), high QE (> 90%) makes development...
The European Southern Observatory together with external research Institutes is building a Multi-Conjugate Adaptive Optics Demonstrator (MAD) to perform wide field of view adaptive optics correction. aim MAD demonstrate on the sky feasibility MCAO technique and evaluate all critical aspects in such kind instrument framework both 2nd generation VLT instrumentation 100-m Overwhelmingly Large Telescope (OWL). module will be installed at one unit telescope Paranal on-sky observations. based two...