Off-axis PSF reconstruction for integral field spectrograph: instrumental aberrations and application to Keck/OSIRIS data

The integral field spectrograph OSIRIS at Keck I has been used to measure the motion of the stars around the supermassive black hole at the Center of the Galaxy. The small field of view provided and the crowding of the region prevent any good PSF estimate. A parallel imager can be used simultaneously to the IFU. However, its distance of 19 arcseconds prevents the observed PSF to be directly applied to the IFU because of anisoplanatism and instrumental aberrations. The Galactic Center Group at UCLA has developed an algorithms to predict PSF variability for Keck AO images (Off-axis PSF reconstruction, AIROPA software package). AIROPA allows us to use the parallel imager to correctly predict the IFU's PSF. We modified this package to adapt it to the case of OSIRIS imager and IFU (AIROPA-IFU) and characterized the instrumental aberrations of both detectors. Here, we present preliminary results of the application of this post-processing tool to OSIRIS datasets of the Galactic Center.