Calibration of EFOSC2 Broadband Linear Imaging Polarimetry. (20th March 2018)

• Record Type: Journal Article
• Authors: Wiersema, K.; Higgins, A. B.; Covino, S.; Starling, R. L. C.
• Is Part Of: Publications of the Astronomical Society of Australia. Volume 35(2018)
• Publication Date: 2018-03-20
• Subjects: instrumentation: polarimeters – techniques: polarimetric; Astronomy -- Periodicals; Southern sky (Astronomy) -- Periodicals; Astrophysics -- Periodicals; Periodicals; 520.5
• DOI: 10.1017/pasa.2018.6
• Languages: English
• ISSNs: 1323-3580

Abstract

Abstract: The European Southern Observatory Faint Object Spectrograph and Camera v2 is one of the workhorse instruments on ESO's New Technology Telescope, and is one of the most popular instruments at La Silla observatory. It is mounted at a Nasmyth focus, and therefore exhibits strong, wavelength and pointing-direction-dependent instrumental polarisation. In this document, we describe our efforts to calibrate the broadband imaging polarimetry mode, and provide a calibration for broadband B, V, and R filters to a level that satisfies most use cases (i.e. polarimetric calibration uncertainty ~0.1%). We make our calibration codes public. This calibration effort can be used to enhance the yield of future polarimetric programmes with the European Southern Observatory Faint Object Spectrograph and Camera v2, by allowing good calibration with a greatly reduced number of standard star observations. Similarly, our calibration model can be combined with archival calibration observations to post-process data taken in past years, to form the European Southern Observatory Faint Object Spectrograph and Camera v2 legacy archive with substantial scientific potential.