WIRC-POL: 0.1% polarimetric precision on-sky with the installation of a HWP modulator
Abstract
WIRC+Pol is a J and H-band linear spectropolarimetric mode for the prime-focus WIRC camera at the Palomar 200-inch Hale telescope. The mode is enabled by a split-pupil polarization grating that allows for the simultaneous measurement of Stokes Q and U without the use of a modulator at a seeing-limited spectral resolving power of ~100. To overcome time-dependent instrumental polarization effects that limited the calibration of instrumental polarization to a ~1% level, in February 2019 we installed a linear polarizer and half-wave plate modulator in front of the instrument, both of which are rotatable. With these two new optics, we are now able to calibrate the instrumental polarization to less than 0.1%. Here we report on WIRC+Pol's post-upgrade on-sky performance, including a polarimetric instrument model that we characterize as a function of time and focal-plane location.
Additional Information
© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE).Attached Files
Published - SPIE-AS20-8e4f6a5e-4d06-ea11-813d-005056be4d05.pdf
Files
SPIE-AS20-8e4f6a5e-4d06-ea11-813d-005056be4d05.pdf
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Identifiers
- Eprint ID
- 107648
- Resolver ID
- CaltechAUTHORS:20210122-074904083
Dates
- Created
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2021-01-22Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
Caltech Custom Metadata
- Caltech groups
- Astronomy Department
- Series Name
- Proceedings of SPIE
- Series Volume or Issue Number
- 11447