First faint dual-field phase-referenced observations on the Keck interferometer
Abstract
Ground-based long baseline interferometers have long been limited in sensitivity by the short integration periods imposed by atmospheric turbulence. The first observation fainter than this limit was performed on January 222, 2011 when the Keck Interferometer observed a K=11.5 target, about one magnitude fainter than its K=10.3 limit. This observation was made possible by the Dual Field Phase Referencing instrument of the ASTRA project: simultaneously measuring the real-time effects of the atmosphere on a nearby bright guide star, and correcting for it on the faint target, integration time longer than the turbulence time scale are made possible. As a prelude to this demonstration, we first present the implementation of Dual Field Phase Referencing on the interferometer. We then detail its on-sky performance focusing on the accuracy of the turbulence correction, and on the resulting fringe contrast stability. We conclude with a presentation of early results obtained with Laser Guide Star AO and the interferometer.
Additional Information
© 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). The W. M. Keck Observatory is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This material is based upon work supported by the National Science Foundation under Grant No. AST-0619965. This material is based in part upon work performed for the Jet Propulsion Laboratory, California Institute of Technology, sponsored by the U.S. Government under Prime Contract NAS7-03001 between the California Institute of Technology and NASA.Attached Files
Published - 84450E.pdf
Submitted - 1207.5019.pdf
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Additional details
- Eprint ID
- 71438
- Resolver ID
- CaltechAUTHORS:20161025-082823683
- W. M. Keck Foundation
- NSF
- AST-0619965
- NASA
- NAS7-03001
- NASA/JPL/Caltech
- Created
-
2016-10-25Created from EPrint's datestamp field
- Updated
-
2021-11-11Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 8445