Changes between Version 234 and Version 235 of AstroTechTalk
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- 25 Oct 2016, 12:30:33 (8 years ago)
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AstroTechTalk
v234 v235 30 30 || '''07.10.2016''' || '''Silvia Scheithauer''' || '''CIAO - Wavefront sensors for GRAVITY[[BR]]'''[[BR]]GRAVITY is a near-infrared instrument for the Very Large Telescope Interferometer (VLTI) at the ESO Paranal observatory in Chile. GRAVITY combines the light of all four 8,2m telescopes to mimic a virtual 130m telescope. The thereby possible, drastically increased sensitivity and resolution, however, can only be reached, if the image blur due to atmospheric turbulence above every single telescope is corrected by the real-time deformable mirrors of an adaptive optics system. Hence, GRAVITY has to provide not only the „Beam Combiner Instrument“ (BCI) in the VLTI-lab, but also four infrared wavefront sensors to analyze the atmospheric turbulence. These wavefront sensors are located in the four Coudé-rooms of the telescopes, therefore called „Coudé Infrared Adaptive Optics“ (CIAO). [[BR]][[BR]]The CIAO wavefront sensors were built under the responsibility of MPIA in close cooperation with ESO and the MPE-led GRAVITY consortium. While the BCI has been installed already in October 2015 on Paranal, the assembly of the four CIAO systems lasted from February to September 2016. Currently, the scientific commissioning of the complete GRAVITY instrument is ongoing.[[BR]][[BR]]One important scientific goal is the observation of objects in the direct vicinity of the black hole in the center of our Milky Way. In addition, GRAVITY will allow to study young stellar objects and shaped-up stars with an unprecedented sensitivity. In spring 2017, when the galactic center is again observable from Paranal, observations of the star „S2“ will start. The close fly-by of this star relative to the black hole will allow to test Einstein's general theory of relativity with an extreme accuracy. [[BR]][[BR]]Presentation: German [[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-10-07_CIAO.pdf Slides: English][[BR]]Questions: German, English || 31 31 || '''14.10.2016''' || '''Claudia Reinlein (Fraunhofer IOF, Jena)''' || '''Active and Adaptive Optics at the Fraunhofer IOF'''[[BR]][[BR]]Active and Adaptive Optics is more and more used in ground-based telescopes and also in discussion for space telescopes. For both types of systems there are completely different technological requirements. While space telescopes mainly aim for active optics, ground-based systems apply both active and adaptive optics.[[BR]][[BR]]This talk describes the technological features and the state of the art of "deformable mirrors / AO systems". And here the focus will be set onto research and development projects of the Fraunhofer IOF (Jena).[[BR]][[BR]]In the framework of an ESA project, a test breadboard is developed, in order to demonstrate the capability to compensate for static aberrations in using active mirrors in space telescopes. In the future, telescopes with a diameter of 4-16m will be used for the search for extraterrestrial life. In this context, IOF develops and investigates an active mirror with "set-and-forget" characteristics to compensate for aberrations conditional of manufacture and assembly. [[BR]][[BR]]For the European Extremely Large Telescope (E-ELT) a technology development for extreme AO (X-AO) is conducted. In this context, the talk will inform about a technological pre-investigation (design) of a deformable mirror with 11000 actuators. [[BR]][[BR]]For laser communication between a ground-station and a geostationary satellite, the pre-compensation of aberrations is a technique to increase the signal intensity at the receiver and to attenuate disturbing speckles. The talk will also present the real-time AO of the Fraunhofer IOF and its compensatory efficiency as a function of the correction angle.[[BR]][[BR]]Presentation: German [[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-10-14_AAO-Fraunhofer.pdf Slides: English][[BR]]Questions: German, English || 32 || '''21.10.2016 '''[[BR]]'''[[span(style=color: #FF0000, HdA-Auditorium!!)]]''' || '''Eike Guenther (TLS, Tautenburg)''' || '''Instrumentation projects of the [[BR]]Thüringer Landessternwarte''' '''Tautenburg '''[[BR]][[BR]]The Thüringer Landessternwarte (TLS) operates a 2m Alfred-Jensch telescope and a LOFAR radio telescope in Tautenburg and is involved in a number of instrumentation projects for various telescopes. In this talk the instrumentation of the telescopes in Tautenburg and other projects are reviewed. [[BR]][[BR]]Although the Alfred-Jensch telescope was built more than 50 years ago, it is continuously upgraded with new instrumentation. Currently in use are a high-resolution Echelle spectrograph, which is used for exoplanet-research, and a low-resolution faint-object spectrograph. Additionally, there is also a CCD camera in the prime-focus, which is used for imaging. Building on the experience with these instruments the TLS also participated in a number of international instrumentation projects. The first one was GROND, a multi-channel camera for the ESO/MPG 2.2m telescope at La Silla. Others were the HERMES spectrograph for the Mercator telescope in La Palma and the two calibration units for CARMENES. Still ongoing is the upgrade of CRIRES to CRIRES+, which is a high-resolution NIR spectrograph for the VLT. Being studied is GTI, a multi-channel camera that is specifically designed for the follow-up observations of exoplanet candidates of TESS and PLATO. [[BR]][[BR]]The TLS also hosts a LOFAR station. LOFAR is the Low-Frequency Array, an instrument for performing radio astronomy in the wavelength range from 1.2 to about 10 m. It is being built by ASTRON, the Netherlands Institute for Radio Astronomy and its international partners, and operated by ASTRON's radio observatory of the Netherlands Organisation for Scientific Research. About 40 stations are located in the Netherlands, additional ones are in Great Britain, France, Sweden, and Germany.[[BR]][[BR]]Presentation: German [[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-10-21_TLS.pdf Slides: English][[BR]]Questions: German, English ||32 || '''21.10.2016 '''[[BR]]'''[[span(style=color: #FF0000, HdA-Auditorium!!)]]''' || '''Eike Guenther + Michael Pluto (TLS, Tautenburg)''' || '''Instrumentation projects of the [[BR]]Thüringer Landessternwarte''' '''Tautenburg '''[[BR]][[BR]]The Thüringer Landessternwarte (TLS) operates a 2m Alfred-Jensch telescope and a LOFAR radio telescope in Tautenburg and is involved in a number of instrumentation projects for various telescopes. In this talk the instrumentation of the telescopes in Tautenburg and other projects are reviewed. [[BR]][[BR]]Although the Alfred-Jensch telescope was built more than 50 years ago, it is continuously upgraded with new instrumentation. Currently in use are a high-resolution Echelle spectrograph, which is used for exoplanet-research, and a low-resolution faint-object spectrograph. Additionally, there is also a CCD camera in the prime-focus, which is used for imaging. Building on the experience with these instruments the TLS also participated in a number of international instrumentation projects. The first one was GROND, a multi-channel camera for the ESO/MPG 2.2m telescope at La Silla. Others were the HERMES spectrograph for the Mercator telescope in La Palma and the two calibration units for CARMENES. Still ongoing is the upgrade of CRIRES to CRIRES+, which is a high-resolution NIR spectrograph for the VLT. Being studied is GTI, a multi-channel camera that is specifically designed for the follow-up observations of exoplanet candidates of TESS and PLATO. [[BR]][[BR]]The TLS also hosts a LOFAR station. LOFAR is the Low-Frequency Array, an instrument for performing radio astronomy in the wavelength range from 1.2 to about 10 m. It is being built by ASTRON, the Netherlands Institute for Radio Astronomy and its international partners, and operated by ASTRON's radio observatory of the Netherlands Organisation for Scientific Research. About 40 stations are located in the Netherlands, additional ones are in Great Britain, France, Sweden, and Germany.[[BR]][[BR]]Presentation: German [[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-10-21_TLS.pdf Slides: English Part1] [https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-10-21_TLS-LOFAR.pdf Part2][[BR]]Questions: German, English || 33 33 || '''28.10.2016''' || '''Santiago Barboza''' || '''The MICADO derotator and its test stand at MPIA'''[[BR]] [[BR]]The Multi-AO Imaging Camera for Deep Observations (MICADO), a first light instrument for the 39m European Extremely Large Telescope (E-ELT), is being designed and optimized to work with the Multi-Conjugate Adaptive Optics (MCAO) module MAORY using laser guide stars. The MICADO-MAORY configuration will provide diffraction limited imaging over a large 53arcsec field of view. [[BR]] [[BR]] The current concept of the MICADO instrument consists of a structural cryostat (2.1m diameter and 2m height) with the wavefront sensor (WFS) on top (cryostat + WFS ≈ 4.000kg). The cryostat is mounted via its central flange directly to a large 2.5m-diameter image derotator. The whole assembly is suspended above the E-ELT Nasmyth platform by a hexapod-type support structure, which is located underneath the MAORY bench.[[BR]] [[BR]] MPIA is responsible for the design and development of the MICADO derotator, a key mechanism that must precisely rotate the cryostat assembly around its optical axis with a differential angular positioning accuracy lower than 10 arcsec, in order to compensate the field rotation due to the alt-azimuth mount of the E-ELT. This device consists of a high precision bearing, gear wheels, motors, encoders and very stiff mechanical interfaces. The MICADO derotator is being developed using a custom-made high-precision four-point contact ball bearing. [[BR]] [[BR]] With the intention of probing the current concept of the derotator in an early phase of the project, a prototype has been built using a standard 1.2m-diameter bearing. The test campaign is about to start during the next days and we will figure out if the proposed concept is able to reach the challenging angular positioning accuracy and other key performance figures required by the MICADO instrument.[[BR]][[BR]]Presentation: English[[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-10-28_MICADODerot.pdf Slides: English][[BR]]Questions: German, English || 34 34 || '''04.11.2016''' || '''Stefan Hippler''' || '''Adaptive optics for VLT and E-ELT'''[[BR]][[BR]]This talk summarizes in a very general approach the principles of adaptive optics (AO) and its value in the astronomical application. In part one, Stefan Hippler will specifically and phenomenoligically descibe how images are formed up during an observation through optical turbulence. A brief historical summary highlighting the achieved experimental milestones will conclude this introduction. [[BR]][[BR]]In part two of the talk, the AO systems of the famous ESO observatories on Paranal (VLT) and Armazones (E-ELT) will be brought into focus. With NACO and CIAO, two examples of already running instruments will be described in detail. This also allows a foresight to the currently designed advanced systems for ESO's new flagship mission in the mid twenty-twenties. [[BR]][[BR]]Presentation: German [[BR]][https://svn.mpia.de/trac/gulli/att/raw-attachment/wiki/AlteVortraege2016S2/2016-11-04_AOOverview.pdf Slides: English][[BR]]Questions: German, English ||