The polarimeter built for the SARG, the high resolution spectrograph of the italian Rlescopio Nazionale Galileo, is presented. Since this polarimeter works with prisms, instead of waveplates, and being the SARG located at a Nasmyth focus, it is very innovative and represents a possible prototype of a new class of instruments. The importance of prisms is related to the almost constant retard along the very large spectral coverage of modern spectrographs, such as the SARG that covers more than 3000 Angstrom in a single exposure. The two flat metallic mirrors, which are necessary to feed the spectrograph, and the alto-azimuthal mounting of the telescope are responsible of an instrumental polarisation depending on the sky position of the target. Thus, the instrumental polarisation has been modelled and successfully subtracted from the observations.
|Titolo:||The High Resolution Spectropolarimeter of the Italian Telescopio Nazionale Galileo|
|Data di pubblicazione:||2003|
|Citazione:||The High Resolution Spectropolarimeter of the Italian Telescopio Nazionale Galileo / Leone F. - 307(2003), pp. 51-57. ((Intervento presentato al convegno Solar Polarization 3 tenutosi a Puerto de la Cruz, Tenerife, Spagna nel 30 Settembre - 4 Ottobre 2002.|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|