Paper
28 July 2008 Phase referencing in optical interferometry
Mercedes E. Filho, Paulo Garcia, Gilles Duvert, Gaspard Duchene, Eric Thiebaut, John Young, Olivier Absil, Jean-Phillipe Berger, Thomas Beckert, Sebastian Hoenig, Dieter Schertl, Gerd Weigelt, Leonardo Testi, Eric Tatuli, Virginie Borkowski, Michaël de Becker, Jean Surdej, Bernard Aringer, Joseph Hron, Thomas Lebzelter, Andrea Chiavassa, Romano Corradi, Tim Harries
Author Affiliations +
Abstract
One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two extremes of phase corruption by the atmosphere. While in radio it is possible to obtain calibrated phases for the science objects, in the optical this is currently not possible. Instead, optical interferometry has relied on closure phase techniques to produce images. Such techniques allow only to achieve modest dynamic ranges. However, with high contrast objects, for faint targets or when structure detail is needed, phase referencing techniques as used in radio interferometry, should theoretically achieve higher dynamic ranges for the same number of telescopes. Our approach is not to provide evidence either for or against the hypothesis that phase referenced imaging gives better dynamic range than closure phase imaging. Instead we wish to explore the potential of this technique for future optical interferometry and also because image reconstruction in the optical using phase referencing techniques has only been performed with limited success. We have generated simulated, noisy, complex visibility data, analogous to the signal produced in radio interferometers, using the VLTI as a template. We proceeded with image reconstruction using the radio image reconstruction algorithms contained in aips imagr (clean algorithm). Our results show that image reconstruction is successful in most of our science cases, yielding images with a 4 milliarcsecond resolution in K band. We have also investigated the number of target candidates for optical phase referencing. Using the 2MASS point source catalog, we show that there are several hundred objects with phase reference sources less than 30 arcseconds away, allowing to apply this technique.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mercedes E. Filho, Paulo Garcia, Gilles Duvert, Gaspard Duchene, Eric Thiebaut, John Young, Olivier Absil, Jean-Phillipe Berger, Thomas Beckert, Sebastian Hoenig, Dieter Schertl, Gerd Weigelt, Leonardo Testi, Eric Tatuli, Virginie Borkowski, Michaël de Becker, Jean Surdej, Bernard Aringer, Joseph Hron, Thomas Lebzelter, Andrea Chiavassa, Romano Corradi, and Tim Harries "Phase referencing in optical interferometry", Proc. SPIE 7013, Optical and Infrared Interferometry, 70131F (28 July 2008); https://doi.org/10.1117/12.787908
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Cited by 1 scholarly publication.
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KEYWORDS
Visibility

Image restoration

Optical interferometry

Image resolution

Stars

Telescopes

Interferometry

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