Since several years the Zurich Imaging polarimeter (ZIMPOL) system is successfully used as a high sensitivity polarimeter. The polarimeter system, which is mainly based on a fast modulator and a special demodulating camera with a masked CCD, has been continuously improved. The third version of the system (ZIMPOL-3) is routinely used at IRSOL, Locarno. The fast modulation allows to “freeze” intensity variations due to seeing, and to achieve a polarimetric sensitivity below 10^-5 if the photon statistics is large enough. In October 2013 the ZIMPOL system has been brought and installed for the first time at the GREGOR telescope in Tenerife for a spectropolarimetric observing campaign. There, the system configuration took advantage from the calibration unit installed at the primary focus of the GREGOR telescope, while the analyzer was inserted in the optical path just before the spectrograph slit after several folding mirrors. This setup has been tested successfully by the authors for the first time in this occasion.

Date Published: 8 July 2014
PDF: 8 pages
Proc. SPIE 9147, Ground-based and Airborne Instrumentation for Astronomy V, 91473G (8 July 2014); doi: 10.1117/12.2056934

Published in SPIE Proceedings Vol. 9147:
Ground-based and Airborne Instrumentation for Astronomy V
Suzanne K. Ramsay; Ian S. McLean; Hideki Takami, Editor(s)