High spatial resolution solar polarimetry with interference filters
Informazioni aggiuntive
Autori
Wiehr E.,
Bianda M.
Tipo
Articolo pubblicato in rivista scientifica
Anno
2003
Lingua
Inglese
Sommario
A new type of two-dimensional polarimeter is used to measure the center-to-limb variation of the scattering induced polarization in a narrow continuum window up to the extreme limb. The polarimeter is set on the Tenerife Gregory Coudé telescope's hour axis, where the two folding flat mirrors cancel their polarizing effects for zero solar declination at the equinox. The short CCD exposure of only 5 ms allows high spatial resolution images in polarized light. A beam switching technique together with an integration parallel to the solar limb over 20arcsec, yields a high polarimetric accuracy with an rms noise of 2*E-4. Our results for a continuum window at 4506-4508 Å agree with model calculations down to limb distances of 0farcs32 (i.e. cos vartheta < 0.025)
Parole chiave
irsol-refereed-scientific-papers
Periodico
Astronomy and Astrophysics
Volume
398
Pagine (o numero dell’articolo)
742-739
