THE GEMINI NICI PLANET-FINDING CAMPAIGN: THE COMPANION DETECTION PIPELINE

Abstract

We present the high-contrast image processing techniques used by the Gemini\nNICI Planet-Finding Campaign to detect faint companions to bright stars. NICI\n(Near Infrared Coronagraphic Imager) is an adaptive optics instrument installed\non the 8-m Gemini South telescope, capable of angular and spectral difference\nimaging and specifically designed to image exoplanets. The Campaign data\npipeline achieves median contrasts of 12.6 magnitudes at 0.5" and 14.4\nmagnitudes at 1" separation, for a sample of 45 stars (V= 4.3-13.9 mag) from\nthe early phase of the Campaign. We also present a novel approach to\ncalculating contrast curves for companion detection based on 95% completeness\nin the recovery of artificial companions injected into the raw data, while\naccounting for the false-positive rate. We use this technique to select the\nimage processing algorithms that are more successful at recovering faint\nsimulated point sources. We compare our pipeline to the performance of the LOCI\nalgorithm for NICI data and do not find significant improvement with LOCI.\n