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The First Diffraction-Limited Images from the W. M. Keck Telescope

Matthews, K. and Ghez, A. M. and Weinberger, A. J. and Neugebauer, G. (1996) The First Diffraction-Limited Images from the W. M. Keck Telescope. Publications of the Astronomical Society of the Pacific, 108 (725). pp. 615-619. ISSN 0004-6280. doi:10.1086/133773.

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The first diffraction limited, 0.05" resolution, images on the W. M. Keck Telescope have been obtained at a wavlength of 2.2 microns. These images were part of an experiment to test the suitability of the Keck Telescope for speckle imaging. In order to conduct this test, it was necessary to modify the pixel scale of the Keck facility Near Infrared Camera (NIRC) to optimally sample the spatial frequencies made available by the Keck Telescope. The design and implementation of the external reimaging optics, which convert the standard f/25 beam from the secondary mirror to f/182 are described here. Techniques for reducing speckle data with field rotation on an alt-az telescope are also described. Three binary stars were observed in this experiment with separations as small as 0.05". With only 100 frames of data on each, a dynamic range of at least 3.5 mag was achieved in all cases. These observations imply that a companion as faint as 14.5 mag at 2.2 microns could be detected around an 11th magnitude point source.

Item Type:Article
Related URLs:
URLURL TypeDescription
Ghez, A. M.0000-0003-3230-5055
Weinberger, A. J.0000-0001-6654-7859
Additional Information:© 1996 Astronomical Society of the Pacific. Received 1996 March 15; accepted 1996 May 1. It is a pleasure to thank the W. M. Keck Foundation and its President, Howard B. Keck, for the generous grant that made the W. M. Keck Observatory possible. We thank the Keck Science Steering Committee for providing funds to construct the NIRC image magnifier, Jerry Nelson, Gary Chanon, and Michael DiVittorio for their work on the Keck optics, Barbara Schaefer and Terry Stickel, the telescope operators during these observations, and Wendy Harrison for assistance with the observations. We also thank Jonathan Kawamura and Sean Lin for their work on designing the image magnifier, Al Conrad for modifying NIRC software to facilitate speckle imaging at Keck, and Beth Klein for helping with the observations. Infrared astronomy at Caltech is supported by grants from the NSF. A. J. W. is supported through the NASA Graduate Student Researchers Program. A. M. G. is supported by a NSF Young Investigator Award.
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
NASA Graduate Student Research FellowshipUNSPECIFIED
Issue or Number:725
Record Number:CaltechAUTHORS:20180130-132414440
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Official Citation:K. Matthews et al 1996 PASP 108 615-619
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:84584
Deposited On:31 Jan 2018 18:17
Last Modified:15 Nov 2021 20:21

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