NICI: combining coronagraphy, ADI, and SDI

TL;DR

NICI is a new high-contrast imaging instrument that uniquely combines coronagraphy, SDI, and ADI techniques, leading to improved exoplanet detection capabilities.

Contribution

First implementation of a single instrument combining coronagraphy, SDI, and ADI techniques for direct imaging of exoplanets.

Findings

Combining SDI and ADI yields significant sensitivity improvements.

Preliminary data demonstrate the effectiveness of the combined techniques.

NICI enables more effective high-contrast imaging at Gemini South.

Abstract

The Near-Infrared Coronagraphic Imager (NICI) is a high-contrast AO imager at the Gemini South telescope. The camera includes a coronagraphic mask and dual channel imaging for Spectral Differential Imaging (SDI). The instrument can also be used in a fixed Cassegrain Rotator mode for Angular Differential Imaging (ADI). While coronagraphy, SDI, and ADI have been applied before in direct imaging searches for exoplanets. NICI represents the first time that these 3 techniques can be combined. We present preliminary NICI commissioning data using these techniques and show that combining SDI and ADI results in significant gains.