Performance of the Near-infrared coronagraphic imager on Gemini-South

TL;DR

This paper evaluates the performance of the NICI instrument on Gemini-South, demonstrating its capabilities in adaptive optics, coronagraphy, and spectral imaging for exoplanet detection, with results aligning well with model predictions.

Contribution

First comprehensive on-sky performance analysis of NICI's subsystems and end-to-end contrast, validating design models for exoplanet imaging.

Findings

NICI achieves high contrast imaging suitable for exoplanet detection.

Subsystem performances closely match model predictions.

End-to-end contrast curves demonstrate NICI's effectiveness in the near-infrared.

Abstract

We present the coronagraphic and adaptive optics performance of the Gemini-South Near-Infrared Coronagraphic Imager (NICI). NICI includes a dual-channel imager for simultaneous spectral difference imaging, a dedicated 85-element curvature adaptive optics system, and a built-in Lyot coronagraph. It is specifically designed to survey for and image large extra-solar gaseous planets on the Gemini Observatory 8-meter telescope in Chile. We present the on-sky performance of the individual subsystems along with the end-to-end contrast curve. These are compared to our model predictions for the adaptive optics system, the coronagraph, and the spectral difference imaging.