Investigating the Polarimetric Capabilities for the Giant Magellan Telescope

Astronomical polarimetry is a powerful tool in the investigation of asymmetries, magnetic fields, and scattering phenomena in and around stars, planets, and galaxies and also in the study of interstellar and circumstellar media.As polarimetry is a photon-starved technique, a polarimetric capability on the next-generation giant segmented mirror telescopes (GSMTs) will enable observations of fainter targets, thereby opening up a wealth of science that cannot be achieved with the current generation of large telescopes.We are investigating the feasibility of adding a polarimetric capability to one of the planned first-generation instruments for the Giant Magellan Telescope (GMT).Here, we present a study of incorporating polarimetric optics into ComCam, the GMT Commissioning Camera.We analyze the performance of the instrument after the integration of a waveplate and Wollaston prism into the pseudo-collimated beam.We also present a design for new ComCam camera optics that are optimized to accommodate the polarimetric optics.Using the technical requirements from the polarimetric science cases, this 'GMT-Pol' version of the instrument delivers seeing-limited performance over a wavelength range of 0.5-0.9 µm with a ∼2 arcmin field-of-view.