An imaging spectropolarimeter for next UV space telescopes

摘要

We are proposing an UV imaging spectro-polarimeter for the next UV space telescopes as WSO/UV. This instrument has been selected as one of the three channels, the Near-UV channel, of the Field Camera Unit at the focal plane of the WSO/UV telescope. Its optical design is based on a Wollaston prism followed by filters selecting the wavelength band and by a spherical mirror and an elliptical convex grating giving the spectral dispersion in the 150-280 nm wavelength range. This instrument allows a circular field of view of 1 arcmin with spatial resolution of 0.03 arcsec/pixel and low spectral resolution. Four different slitless operational modes will be possible: the imaging mode and the polarimetric mode, substituting the grating for an elliptical mirror and including or not the Wollaston prism, the spectral mode, excluding the Wollaston prism from the optical path, and the spectro-polarimetric mode, including all the optical elements in front of the entering radiation beam.