WIRC-POL: 0.1% polarimetric precision on-sky with the installation of a HWP modulator

Maxwell Andrew Millar-Blanchaer; Samaporn Tinyanont; Nemanja Jovanovic; Dimitri Mawet; Gautam Vasisht; Jennifer W. Milburn; Eugene Serabyn; Michael Porter; Skyler Palatnick; Connor Hopkins

doi:10.1117/12.2562762

7 March 2021 WIRC-POL: 0.1% polarimetric precision on-sky with the installation of a HWP modulator

Maxwell Andrew Millar-Blanchaer, Samaporn Tinyanont, Nemanja Jovanovic, Dimitri Mawet, Gautam Vasisht, Jennifer W. Milburn, Eugene Serabyn, Michael Porter, Skyler Palatnick, Connor Hopkins

Author Affiliations +

Proceedings Volume 11447, Ground-based and Airborne Instrumentation for Astronomy VIII; 114475Y (2021) https://doi.org/10.1117/12.2562762
Event: SPIE Astronomical Telescopes + Instrumentation, 2020, Online Only

Conference Poster

Abstract

WIRC+Pol is a J and H-band spectropolarimetric mode for the prime-focus WIRC camera at the Palomar 200-inch Hale telescope. The mode has been enabled with the installation of a split-pupil polarization grating in Feburary 2017. The polarization grating was designed for the simultaneous measurement of Stokes Q and U without the use of a modulator at a seeing-limited spectral resolving power of 100. WIRC+Pol can operate in both a slitless mode and with a 3” slit. 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 this design the primary mirror is the only optic in front of the modulator. The new upgrade has allowed us to calibrate the instrumental polarization to less than 0.1%. Here we present a detailed description of the upgrade and report on WIRC+Pol’s post-upgrade on-sky performance based on observations of unpolarized and polarized standard stars. We have used the observations of polarized standard stars to develop a wavelength-dependent polarimetric instrument model that we characterize as a function of time and focal-plane location.

Citation Download Citation

Maxwell Andrew Millar-Blanchaer, Samaporn Tinyanont, Nemanja Jovanovic, Dimitri Mawet, Gautam Vasisht, Jennifer W. Milburn, Eugene Serabyn, Michael Porter, Skyler Palatnick, and Connor Hopkins "WIRC-POL: 0.1% polarimetric precision on-sky with the installation of a HWP modulator", Proc. SPIE 11447, Ground-based and Airborne Instrumentation for Astronomy VIII, 114475Y (7 March 2021); https://doi.org/10.1117/12.2562762

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available