Modeling instrumental field-dependent aberrations in the NIRC2 instrument on the Keck II telescope
Abstract
We present a model of field-dependent aberrations arising in the NIRC2 instrument on the W. M. Keck II telescope. We use high signal-to-noise phase diversity data employing a source in the Nasmyth focal plane to construct a model of the optical path difference as a function of field position and wavelength. With a differential wavefront error of up to 190 nm, this effect is one of the main sources of astrometric and photometric measurement uncertainties. Our tests of temporal stability show sufficient reliability for our measurements over a 20-month period at the field extrema. Additionally, while chromaticity exists, applying a correction for field-dependent aberrations provides overall improvement compared to the existing aberrations present across the field of view.
Additional Information
© 2014 SPIE. We would like to acknowledge the financial support of the W. M. Keck Foundation for this project. AMG and MM are also supported by NSF AST-0909218. The authors would also like to thank Jay Anderson, Richard Dekaney, Brent Ellerbroek, James Graham, Claire Max, Andrei Tokovinin, and Marcos van Dam for their valuable input to the project. BNS would also like to thank Saundra Albers.Attached Files
Published - Sitarski_2014p91486T.pdf
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Additional details
- Eprint ID
- 61126
- Resolver ID
- CaltechAUTHORS:20151014-153707078
- W. M. Keck Foundation
- NSF
- AST-0909218
- Created
-
2015-10-14Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 9148