D. Ziegler

Publications (6)31.2 Total impact

• Source

  Available from: Rainer Lenzen

  Article: GRAVITY: Observing the Universe in Motion

  F Eisenhauer, G Perrin, W Brandner, C Straubmeier, K Perraut, A Amorim, M Schöller, S Gillessen, P Kervella, M Benisty, [......], R Davies, D Rouan, M Wittkowski, K Dodds-Eden, D Ziegler, F Cassaing, H Bonnet, M Casali, R Genzel, P Lena
  The Messenger. 03/2011; 143:16-24.
• Source

  Available from: Marcus Haug

  Article: GRAVITY: a four-telescope beam combiner instrument for the VLTI

  S. Gillessen, F. Eisenhauer, G. Perrin, W. Brandner, C. Straubmeier, K. Perraut, A Amorim, M. Schöller, C. Araujo-Hauck, H. Bartko, [......], J. M. Rees, R. R. Rohloff, D. Rouan, G. Rousset, A. Sevin, M Thiel, K Wagner, M. Wiest, S. Yazici, D. Ziegler
  [show abstract] [hide abstract]
  ABSTRACT: GRAVITY is an adaptive optics assisted Beam Combiner for the second generation VLTI instrumentation. The instrument will provide high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the astronomical K-band for faint objects. We describe the wide range of science that will be tackled with this instrument, highlighting the unique capabilities of the VLTI in combination with GRAVITY. The most prominent goal is to observe highly relativistic motions of matter close to the event horizon of Sgr A*, the massive black hole at center of the Milky Way. We present the preliminary design that fulfils the requirements that follow from the key science drivers: It includes an integrated optics, 4-telescope, dual feed beam combiner operated in a cryogenic vessel; near-infrared wavefrontsensing adaptive optics; fringe-tracking on secondary sources within the field of view of the VLTI and a novel metrology concept. Simulations show that 10 {\mu}as astrometry within few minutes is feasible for a source with a magnitude of mK = 15 like Sgr A*, given the availability of suitable phase reference sources (mK = 10). Using the same setup, imaging of mK = 18 stellar sources in the interferometric field of view is possible, assuming a full night of observations and the corresponding UV coverage of the VLTI. Comment: 20 pages, Proceedings SPIE Astronomical Telescopes and Instrumentation Conference 2010
  07/2010;
• Article: GRAVITY: microarcsecond astrometry and deep interferometric imaging with the VLTI

  F. Eisenhauer, G. Perrin, C. Straubmeier, W. Brandner, A. Boehm, F. Cassaing, Y. Clenet, K. Dodds-Eden, A. Eckart, P. Fedou, [......], J. M. Reess, R. R. Rohloff, D. Rouan, G. Rousset, B. Ruyet, M. Schropp, B. Talureau, M. Thiel, J. Ziegleder, D. Ziegler
  [show abstract] [hide abstract]
  ABSTRACT: We present the adaptive optics assisted, near-infrared VLTI instrument GRAVITY for precision narrow-angle astrometry and interferometric phase referenced imaging of faint objects. With its two fibers per telescope beam, its internal wavefront sensors and fringe tracker, and a novel metrology concept, GRAVITY will not only push the sensitivity far beyond what is offered today, but will also advance the astrometric accuracy for UTs to 10 μas. GRAVITY is designed to work with four telescopes, thus providing phase referenced imaging and astrometry for 6 baselines simultaneously. Its unique capabilities and sensitivity will open a new window for the observation of a wide range of objects, and — amongst others — will allow the study of motion within a few times the event horizon size of the Galactic Center black hole.
  Proceedings of the International Astronomical Union 09/2007; 3:100 - 101.
• Source

  Available from: Sébastien Vergnole

  Article: Interferometric coupling of the Keck telescopes with single-mode fibers.

  G Perrin, J Woillez, O Lai, J Guérin, T Kotani, P L Wizinowich, D Le Mignant, M Hrynevych, J Gathright, P Léna, [......], C Marlot, M Marteaud, B-T Melse, J Nishikawa, J-M Reess, S T Ridgway, F Rigaut, K Roth, A T Tokunaga, D Ziegler
  [show abstract] [hide abstract]
  ABSTRACT: Here we report successful interferometric coupling of two large telescopes with single-mode fibers. Interference fringes were obtained in the 2- to 2.3-micrometer wavelength range on the star 107 Herculis by using the two Keck 10-meter telescopes, each feeding their common interferometric focus with 300 meters of single-mode fibers. This experiment demonstrates the potential of fibers for future kilometric arrays of telescopes and is the first step toward the 'OHANA (Optical Hawaiian Array for Nanoradian Astronomy) interferometer at the Mauna Kea observatory in Hawaii. It opens the way to sensitive optical imagers with resolutions below 1 milli-arc second. Our experimental setup can be directly extended to large telescopes separated by many hundreds of meters.
  Science 02/2006; 311(5758):194. · 31.20 Impact Factor
• Article: GRAVITY: a four-telescope beam combiner instrument for the VLTI

  S. Gillessen, F. Eisenhauer, G. Perrin, W. Brandner, C. Straubmeier, K. Perraut, A Amorim, M. Schöller, C. Araujo-Hauck, H. Bartko, [......], J. M. Rees, R. R. Rohloff, D. Rouan, G. Rousset, A. Sevin, M Thiel, K Wagner, M. Wiest, S. Yazici, D. Ziegler
  [show abstract] [hide abstract]
  ABSTRACT: GRAVITY is an adaptive optics assisted Beam Combiner for the second generation VLTI instrumentation. The instrument will provide high-precision narrow-angle astrometry and phase-referenced interferometric imaging in the astronomical K-band for faint objects. We describe the wide range of science that will be tackled with this instrument, highlighting the unique capabilities of the VLTI in combination with GRAVITY. The most prominent goal is to observe highly relativistic motions of matter close to the event horizon of Sgr A*, the massive black hole at center of the Milky Way. We present the preliminary design that fulfils the requirements that follow from the key science drivers: It includes an integrated optics, 4-telescope, dual feed beam combiner operated in a cryogenic vessel; near-infrared wavefrontsensing adaptive optics; fringe-tracking on secondary sources within the field of view of the VLTI and a novel metrology concept. Simulations show that 10 μas astrometry within few minutes is feasible for a source with a magnitude of mK = 15 like Sgr A*, given the availability of suitable phase reference sources (mK = 10). Using the same setup, imaging of mK = 18 stellar sources in the interferometric field of view is possible, assuming a full night of observations and the corresponding UV coverage of the VLTI.
  Danchi, William C.; Delplancke, Françoise; Rajagopal, Jayadev K.: Optical and Infrared Interferometry II %R 10.1117/12.856689, SPIE, 77340Y-77340Y-20 (2010).
• Article: GRAVITY: microarcsecond astrometry and deep interferometric imaging with the VLT

  F. Eisenhauer, G. Perrin, W. Brandner, C. Straubmeier, A Böhm, H. Baumeister, F. Cassaing, Y. Clénet, K. Dodds-Eden, A. Eckart, [......], J. R. Ramos, J. M. Reess, R. R. Rohloff, D. Rouan, G. Rousset, B. Ruyet, A. Sevin, M Thiel, J. Ziegleder, D. Ziegler
  [show abstract] [hide abstract]
  ABSTRACT: We present the AO assisted, near-infrared VLTI instrument GRAVITY for precision narrow-angle astrometry and interferometric phase referenced imaging of faint objects. With its two fibers per telescope beam, its internal wavefront sensors and fringe tracker, and a novel metrology concept, GRAVITY will not only push the sensitivity far beyond what is offered today, but will also advance the astrometric accuracy for UTs to 10 muas. GRAVITY is designed to work with four telescopes, thus providing phase referenced imaging and astrometry for 6 baselines simultaneously. Its unique capabilities and sensitivity will open a new window for the observation of a wide range of objects, and---amongst others---will allow the study of motions within a few times the event horizon size of the Galactic Center black hole.
  Moorwood, Alan F. M.: Science with the VLT in the ELT Era, Springer, 361-368 (2009).