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The ability of NICMOS to perform high accuracy polarimetry is currently hampered by an uncalibrated residual instrumental polarization at a level of 1.2-1.5%. To better quantify and characterize this residual we obtained observations of…

The findings of a nine orbit calibration plan carried out during HST Cycle 15, to fully determine the NICMOS camera 2 (2.0 micron) polarization calibration to high accuracy, are reported. Recently Ueta et al. and Batcheldor et al. have…

We report on the results of calibrating and simulating the instrumental polarization properties of the ESO VLT adaptive optics camera system NAOS/CONICA (NACO) in the Ks-band. We use the Stokes/Mueller formalism for metallic reflections to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 G. Witzel , A. Eckart , R. M. Buchholz , M. Zamaninasab , R. Lenzen , R. Schödel , C. Araujo , N. Sabha , M. Bremer , V. Karas , C. Straubmeier , K. Muzic

Well-calibrated spectropolarimetry studies at resolutions of $R>$10,000 with signal-to-noise ratios (SNRs) better than 0.01\% across individual line profiles, are becoming common with larger aperture telescopes. Spectropolarimetric studies…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 David Harrington , J. R. Kuhn , Rebecca Nevin

Calibration of instrumental polarization is critical for measuring polarized radio emissions from astrophysical sources to extract the magnetic field information in astrophysical, heliospheric, and terrestrial plasmas. At meter wavelengths,…

Instrumentation and Methods for Astrophysics · Physics 2025-05-08 Devojyoti Kansabanik , Angelos Vourlidas , Soham Dey , Surajit Mondal , Divya Oberoi

We present a characterization of CasPol, a dual-beam polarimeter mounted at the 2.15 meter Jorge Sahade Telescope, located at the Complejo Astron\'omico El Leoncito, Argentina. The telescope is one of the few available meter-sized optical…

Instrumentation and Methods for Astrophysics · Physics 2019-04-11 M. S. Sosa , C. von Essen , I. Andruchow , S. A. Cellone , L. A. Mammana

The value of accurately knowing the absolute calibration of the polarizing elements in the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) becomes especially important when conducting studies which require measuring degrees of…

Astrophysics · Physics 2009-11-11 D. Batcheldor , A. Robinson , D. Axon , D. C. Hines , W. Sparks , C. Tadhunter

The Calar Alto Fiber-fed \'Echelle spectrograph (CAFE) is a high-resolution spectrographs with high-precision radial velocity capabilities mounted in the 2.2m telescope of Calar Alto Observatory. It suffered from strong degradation after 4…

In this paper we present an error analysis for polarimetric data obtained with dual-beam instruments. After recalling the basic concepts, we introduce the analytical expressions for the uncertainties of polarization degree and angle. These…

Astrophysics · Physics 2009-11-11 Ferdinando Patat , Martino Romaniello

Linear polarization can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear polarization increases withthe degree of oblateness, which is inversely proportional to the…

Solar and Stellar Astrophysics · Physics 2017-05-03 E. Manjavacas , P. A. Miles-Páez , M. R. Zapatero-Osorio , B. Goldman , E. Buenzli , T. Henning , E. Pallé , M. Fang

SCExAO at the Subaru telescope is a visible and near-infrared high-contrast imaging instrument employing extreme adaptive optics and coronagraphy. The instrument feeds the near-infrared light (JHK) to the integral-field spectrograph CHARIS.…

Direction-dependent instrumental polarisation introduces wide-field polarimetric aberrations and limits the dynamic range of low-frequency interferometric images. We therefore provide a detailed two-dimensional analysis of the Giant…

Instrumentation and Methods for Astrophysics · Physics 2014-07-03 J. S. Farnes

We report on full-Stokes L-band observations of 98 MeerKAT calibration sources. Linear polarization is detected in 71 objects above a fractional level of 0.2\%. We identify ten sources with strong fractional linear polarization and low…

Astrophysics of Galaxies · Physics 2024-05-24 A. R. Taylor , L. S. Legodi

We reduced ESO's archival linear spectropolarimetry data (4000-9000\AA) of 6 highly polarized and 8 unpolarized standard stars observed between 2010 and 2016, for a total of 70 epochs, with the FOcal Reducer and low dispersion Spectrograph…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 Aleksandar Cikota , Ferdinando Patat , Stefan Cikota , Tamar Faran

We designed, built, and calibrated a new spectropolarimeter for the HiVIS spectrograph (R 12000-49000) on the AEOS telescope. We also did a polarization calibration of the telescope and instrument. We will introduce the design and use of…

Astrophysics · Physics 2009-11-11 D. M. Harrington , J. R. Kuhn , K. Whitman

SCExAO at the Subaru telescope is a visible and near-infrared high-contrast imaging instrument employing extreme adaptive optics and coronagraphy. The instrument feeds the near-infrared light (JHK) to the integral field spectrograph CHARIS.…

We recently commissioned the polarimetric upgrade of the HARPS spectrograph at ESO's 3.6-m telescope at La Silla, Chile. The HARPS polarimeter is capable of full Stokes spectropolarimetry with large sensitivity and accuracy, taking…

This paper is devoted to the primary spectro-polarimetric observation performed at the New Vacuum Solar Telescope of China since 2017, and our aim is to precisely evaluate the real polarimetric accuracy and sensitivity of this polarimetry…

Solar and Stellar Astrophysics · Physics 2020-05-06 Jun-Feng Hou , Zhi Xu , Shu Yuan , Yu-Chao Chen , Jian-Guo Peng , Dong-Guang Wang , Jun Xu , Yuan-Yong Deng , Zhen-Yu Jin , Kai-Fan Ji , Zhong Liu

RoboPol is a four-channel, one-shot linear optical polarimeter that has been successfully operating since 2013 on the 1.3 m telescope at Skinakas Observatory in Crete, Greece. Using its unique optical system, it measures the linear Stokes…

Instrumentation and Methods for Astrophysics · Physics 2024-07-23 Siddharth Maharana , Dmitry Blinov , A. N. Ramaprakash , Vasiliki Pavlidou , Konstantinos Tassis

The High Frequency Instrument of Planck will map the entire sky in the millimeter and sub-millimeter domain from 100 to 857 GHz with unprecedented sensitivity to polarization ($\Delta P/T_{\tiny cmb} \sim 4\cdot 10^{-6}$) at 100, 143, 217…

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