The Near-Infrared Spectrograph (NIRSpec) is one the four focal plane instruments on the James Webb Space Telescope (JWST) which was launched on December 25, 2021. We present the in-flight status and performance of NIRSpec's detector system as derived from the instrument commissioning data. The instrument features two 2048 x 2048 HAWAII-2RG sensor chip assemblies (SCAs) that are operated at a temperature of about 42.8 K and are read out via a pair of SIDECAR ASICs. NIRSpec supports "Improved Reference Sampling and Subtraction" (IRS2) readout mode that was designed to meet NIRSpec's stringent noise requirements and to reduce 1/f and correlated noise. In addition, NIRSpec features subarrays optimized for bright object time series observations, e.g. for the observation of exoplanet transit around bright host stars. We focus on the dark signal as well as the read and total noise performance of the detectors.
@article{arxiv.2208.12686,
title = {The In-Flight Noise Performance of the JWST/NIRSpec Detector System},
author = {Stephan M. Birkmann and Giovanna Giardino and Marco Sirianni and Pierre Ferruit and Bernhard Rauscher and Catarina Alves de Oliveira and Torsten Böker and Nimisha Kumari and Nora Lützgendorf and Elena Manjavacas and Charles Proffitt and Timothy D. Rawle and Maurice te Plate and Peter Zeidler},
journal= {arXiv preprint arXiv:2208.12686},
year = {2022}
}