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Gemini Planet Imager Observational Calibrations VII: On-Sky Polarimetric Performance of the Gemini Planet Imager
- Publication Year :
- 2014
- Publisher :
- arXiv, 2014.
-
Abstract
- We present on-sky polarimetric observations with the Gemini Planet Imager (GPI) obtained at straight Cassegrain focus on the Gemini South 8-m telescope. Observations of polarimetric calibrator stars, ranging from nearly unpolarized to strongly polarized, enable determination of the combined telescope and instrumental polarization. We find the conversion of Stokes $I$ to linear and circular instrumental polarization in the instrument frame to be $I \rightarrow (Q_{\rm IP}, U_{\rm IP}, P_{\rm IP}, V_{\rm IP}) = (-0.037 \pm 0.010\%, +0.4338 \pm 0.0075\%, 0.4354 \pm 0.0075\%, -6.64 \pm 0.56\%)$. Such precise measurement of instrumental polarization enables $\sim 0.1\%$ absolute accuracy in measurements of linear polarization, which together with GPI's high contrast will allow GPI to explore scattered light from circumstellar disk in unprecedented detail, conduct observations of a range of other astronomical bodies, and potentially even study polarized thermal emission from young exoplanets. Observations of unpolarized standard stars also let us quantify how well GPI's differential polarimetry mode can suppress the stellar PSF halo. We show that GPI polarimetry achieves cancellation of unpolarized starlight by factors of 100-200, reaching the photon noise limit for sensitivity to circumstellar scattered light for all but the smallest separations at which the calibration for instrumental polarization currently sets the limit.<br />Comment: 11 pages, 3 figures. Proceedings of the SPIE, 9147-305
- Subjects :
- 010504 meteorology & atmospheric sciences
media_common.quotation_subject
Polarimetry
FOS: Physical sciences
Astrophysics::Cosmology and Extragalactic Astrophysics
Astrophysics
01 natural sciences
law.invention
Telescope
law
0103 physical sciences
Astrophysics::Solar and Stellar Astrophysics
Gemini Planet Imager
010303 astronomy & astrophysics
Instrumentation and Methods for Astrophysics (astro-ph.IM)
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
media_common
Physics
Earth and Planetary Astrophysics (astro-ph.EP)
Linear polarization
Astrophysics::Instrumentation and Methods for Astrophysics
Polarization (waves)
Exoplanet
Stars
13. Climate action
Sky
Astrophysics::Earth and Planetary Astrophysics
Astrophysics - Instrumentation and Methods for Astrophysics
Astrophysics - Earth and Planetary Astrophysics
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....a0e689a367f76ab31b364988fd791cc5
- Full Text :
- https://doi.org/10.48550/arxiv.1407.2307