X-ray polarimetric measurements are based on the study of distributions of the directions of scattered photons or photoelectrons and the search of a sinusoidal modulation with a period of π. We present a new simple tool based on a scatter plot of the modulation curve in which the counts in each angular bin are reported after a shifting by 1/4 of the period. The sinusoidal pattern is thus transformed in a circular plot whose radius is equal to the amplitude of the modulation, while for a not polarized radiation the scatter plot is reduced to a random point distribution centred at the mean frequency value. The advantage of this tool is that one can easily evaluate the statistical significance of the polarimetric detection and can obtain useful information on the quality of the measurement.

Date Published: 11 July 2016
PDF: 6 pages
Proc. SPIE 9905, Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray, 99054I (11 July 2016); doi: 10.1117/12.2240683

Published in SPIE Proceedings Vol. 9905:
Space Telescopes and Instrumentation 2016: Ultraviolet to Gamma Ray
Jan-Willem A. den Herder; Tadayuki Takahashi; Marshall Bautz, Editor(s)