Bright-Moon sky as a wide-field linear Polarimetric flat source for calibration
Journal article, 2023
Context. Next-generation wide-field optical polarimeters such as Wide-Area Linear Optical Polarimeters (WALOPs) have a field of view (FoV) of tens of arcminutes. Wide-field polarimetric flat sources are essential to the efficient and accurate calibration of these instruments. However, no established wide-field polarimetric standard or flat sources exist at present. Aims. This study tests the feasibility of using the polarized sky patches of the size of around 10 × 10 arcminutes2, at a distance of up to 20 from the Moon, on bright-Moon nights as a wide-field linear polarimetric flat source. Methods. We observed 19 patches of the sky adjacent to the bright-Moon with the RoboPol instrument in the SDSS-r broadband filter. These patches were observed on five nights within two days of the full-Moon across two RoboPol observing seasons. Results. We find that for 18 of the 19 patches, the uniformity in the measured normalized Stokes parameters q and u is within 0.2%, with 12 patches exhibiting uniformity within 0.07% or better for both q and u simultaneously, making them reliable and stable wide-field linear polarization flats. Conclusions. We demonstrate that the sky on bright-Moon nights is an excellent wide-field linear polarization flat source. Various combinations of the normalized Stokes parameters q and u can be obtained by choosing suitable locations of the sky patch with respect to the Moon.
Moon
Techniques: polarimetric
Atmospheric effects
Instrumentation: polarimeters
Author
S. Maharana
South African Astronomical Observatory
University of Crete
Inter-University Centre for Astronomy and Astrophysics
Foundation for Research and Technology Hellas (FORTH)
S. Kiehlmann
University of Crete
Foundation for Research and Technology Hellas (FORTH)
D. Blinov
Foundation for Research and Technology Hellas (FORTH)
University of Crete
V. Pelgrims
University of Crete
Université libre de Bruxelles (ULB)
Foundation for Research and Technology Hellas (FORTH)
V. Pavlidou
University of Crete
Foundation for Research and Technology Hellas (FORTH)
Konstantinos Tassis
University of Crete
Foundation for Research and Technology Hellas (FORTH)
J. A. Kypriotakis
Foundation for Research and Technology Hellas (FORTH)
University of Crete
A. N. Ramaprakash
Foundation for Research and Technology Hellas (FORTH)
California Institute of Technology (Caltech)
Inter-University Centre for Astronomy and Astrophysics
R. M. Anche
University of Arizona
A. Basyrov
University of Oslo
K. Deka
Narodowe Centrum Badan Jadrowych
Homi Bhabha National Institute (HBNI)
H. K. Eriksen
University of Oslo
T. Ghosh
Homi Bhabha National Institute (HBNI)
E. Gjerløw
University of Oslo
N. Mandarakas
Foundation for Research and Technology Hellas (FORTH)
University of Crete
E. Ntormousi
Foundation for Research and Technology Hellas (FORTH)
University of Crete
Georgia Panopoulou
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A. Papadaki
Foundation for Research and Technology Hellas (FORTH)
Institute of Computer Science Crete
University of Crete
T. J. Pearson
California Institute of Technology (Caltech)
S. B. Potter
University of Johannesburg
South African Astronomical Observatory
A. C.S. Readhead
California Institute of Technology (Caltech)
Foundation for Research and Technology Hellas (FORTH)
R. Skalidis
California Institute of Technology (Caltech)
I. K. Wehus
University of Oslo
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 679 A68Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1051/0004-6361/202346830