Changes between Version 1 and Version 2 of OldPresentations2018S2

8 Jan 2019, 09:41:15 (5 years ago)
Ralph Hofferbert



  • OldPresentations2018S2

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     1||'''Date''' ||'''Speaker    ''' ||'''Topic''' ||
     2|| '''28.09.2018[[BR]](11hrs, MPIA Hoersaal)''' || '''Prashant Pathak (ESO)''' || '''Closed-loop correction of  atmospheric dispersion for high-contrast coronography and astrometry'''[[BR]][[BR]]On ground-based telescopes employing adaptive optics (AO) systems,  atmospheric dispersion compensation is essential to deliver high-quality  imaging, and critical for coronagraphy and high-precision astrometry.  Imperfect compensation by  an atmospheric dispersion compensator (ADC) can be addressed with a  high-precision on-sky measurement of residual dispersion in a  closed-loop control scheme. [[BR]][[BR]]In this talk, Prashant Pathak will present a focal plane  based technique, which utilizes the chromatic scaling of speckles  to measure residual dispersion (atmospheric and optical) in the final  science image. The residual dispersion can be accurately measured and  subsequently corrected in a closed-loop control. On-sky residual  dispersion of < 1 mas across H-band was demonstrated,  which reduced from 8.4 mas before closing the loop.[[BR]][[BR]]Presentation: English[[BR]][ Slides: English][[BR]]Questions: German, English ||
     3|| 05.10.2018 || || ||
     4|| '''12.10.2018[[BR]](11hrs, MPIA Hoersaal)''' || '''Hans-Ulrich Kaeufl (ESO)''' || '''NEAR - Planet search around Alpha Centauri with VISIR[[BR]]'''[[BR]]ESO, in collaboration with the Breakthrough Initiatives, modifies the  Very Large Telescope mid-IR imager (VISIR) to further boost the high  dynamic range imaging capability this instrument has, by adding a  dedicated coronagraph. This enables a meaningful search for potentially habitable planets  around both Alpha Cen1 and 2. Meaningful here means, achieving a  contrast of ~10^-6^ within ~0.8arcsec from the star while maintaining  basically the normal sensitivity of VISIR. For risk mitigation all components are being tested and qualified under  realistic conditions in the lab at ESO headquarters before integration  into the instrument.  [[BR]] [[BR]]Hans-Ulrich Kaeufl will give an overview of [[BR]]- the optical changes to VISIR [[BR]]- the implementation of wave front sensing [[BR]]- the Dicke switch (fast chopping for noise suppression) design and laboratory testing [[BR]]- the Annular Groove Phase Mask design and laboratory testing [[BR]]- non common path error control with a ZELDA mask [[BR]]- sensitivity and contrast estimates [[BR]]- data flow and analysis [[BR]]- the overall project status, plan and outlook [[BR]] [[BR]]Needless to say that this project is of critical interest for future  infrared instrumentation at the next generation of extremely large  telescopes aiming at surveying the solar neighbourhood for terrestrial  planets by detecting and characterizing them based on their mid-IR  fluxes. Therefore some emphasis will be put on the verification of the  novel chopper system, the Dicke switch.[[BR]][[BR]]Presentation: German[[BR]][ Slides: English][[BR]]Questions: German, English ||
     5|| 19.10.2018 || || ||
     6|| '''26.10.2018[[BR]](11hrs, MPIA Hoersaal)''' || '''Armin Huber''' || '''Slide-Show:[[BR]]Life at the VLT - Part 2 of the famous photo reportage'''[[BR]][[BR]]Today, Armin Huber will present us some impressions of how installation work at the Very large Telescope (VLT) looks like. To make it a complete story, he certainly will also talk about the trip to Chile, the accommodation and food options, and last but not least the recreation possibilities.[[BR]][[BR]]And while part 1 about the LBT included Native Americans and Red Squirrels, this time we will hear about James Bond and a swimming pool at a height of 2400m ASL.[[BR]] [[BR]]Lots of photos - only a little text. [[BR]] [[BR]]Presentation: German ||
     7|| 02.11.2018 || -- || Bridging day after All Saints's Day ||
     8|| '''09.11.2018[[BR]](11hrs, MPIA Hoersaal)''' || '''Faustine Cantalloube''' || '''Peering through the SPHERE high contrast images[[BR]]'''[[BR]]When looking at the VLT/SPHERE images we can already infer a few error  terms that were expected when designing the instrument. But when going  deeper in contrast there may arise some new error terms that were not  expected. This talk presents a review of all these terms, based on what we can  now see in the focal plane images. [[BR]][[BR]]Faustine Cantalloube will then focus on one of the main  killers of high contrast imaging: the wind driven halo which appears in the  images when the turbulence is evolving faster than the AO correction  loop frequency could account for. For detection of extended features, this effect is  affecting the detection capabilities at short separation (below 300mas),  which is the region of interest for most science cases. This talk is a  short review of this effect, including its recently acknowledged  asymmetry and potential solutions to get over it.[[BR]][[BR]]Presentation: English[[BR]][ Slides: English][[BR]]Questions: German, English ||
     9|| 16.11.2018 || || ||
     10|| 23.11.2018 || || ||
     11|| 30.11.2018 || || ||
     12|| '''07.12.2018 [[BR]](11hrs, MPIA Hoersaal)''' || '''Wolfgang Brandner''' || '''Surveying the galactic center of our Milky way with VLTI'''[[BR]][[BR]]Hidden behind dense dark clouds of dust and gas, and hence optically invisible, a super massive black hole populates the center of our Milky Way.  Since September 2016 the interferometric instrument GRAVITY and the MPIA provided Coudé Infrared Adaptive Optics (CIAO) allow for the very first time the simultaneous interferometric observation of the galactic center with all four 8m telescopes of ESO's Very Large Telescope Interferometer (VLTI). Goal is to better understand the physical effects in this central region.[[BR]][[BR]]After a short introduction of interferometry with GRAVITY+CIAO, Wolfgang Brandner  will give an overview of the observational results of the first two years at VLTI. The prime science cases were the tracking of a star during its passage at smallest distance to the galactic center and the investigation of brightness fluctuations at the closest proximity to the black hole. The motion of the star allows to determine the mass of the black hole and the distance to the sun with high precision. Furthermore, the measured data allow for a comparison with effects of Einstein's special and general theorie of relativity. The results indicate that Einstein's predictions are also valid in the direct vicinity of the super massive black hole in the center of our Milky Way.[[BR]][[BR]]Presentation: German[[BR]][ Slides: English][[BR]]Questions: German, English ||
     13|| '''14.12.2018[[BR]](11hrs, HdA Auditorium)''' || '''Bernd Carsten Sander (ZARM)''' || '''The Drop-Tower in Bremen - Weightless on Earth'''[[BR]][[BR]]The drop-tower in Bremen is a unique research facility in Europe, where everyday since 1990 scientific and technological experiments at zero gravity conditions are conducted. During the free fall from a height of 120m inside the tower, zero gravity is given for 4,74  seconds. Since 2004 a catapult-system allows to double this duration to 9,3 seconds. [[BR]][[BR]]The possible experiments span the complete range from knowledge-based and application-oriented fundamental research up to product design, especially in fluid mechanics, rheology, combustion and thermodynamics, as well as in material research, physics and biology. In addition, the proper functionality of spaceborne instruments is verified in this zero gravity environment before their nominal use in space.[[BR]][[BR]]Presentation: German[[BR]][ Slides: English][[BR]]Questions: German, English ||
     14|| 21.12.2018 || || ||
     15|| 28.12.2018 || -- || Christmas Break ||