Impact of Optical Ghosts in Rubin Commissioning Data

Abstract

Optical ghosts are image artifacts caused by successive reflections of light between optical surfaces such as lenses, filters, and detectors. These artifacts are unavoidable due to the nonzero reflectances of optical elements and are a major source of contamination for low-surface-brightness science. We use optical ray tracing simulations tuned to observations from LSST Commissioning to quantify the impact of optical ghosts on the LSST data. In particular, we find that  ∼ 0.57% of the LSSTCam focal plane is impacted by optical ghosts when averaged across all bands.