The InfraRed Imaging Spectrograph (IRIS) for TMT: photometric characterization of anisoplanatic PSFs and testing of PSF-Reconstruction via AIROPA

TL;DR

This paper evaluates the photometric accuracy of the IRIS instrument on TMT, focusing on PSF variability due to anisoplanatism, and tests the effectiveness of PSF-Reconstruction algorithms using AIROPA software.

Contribution

It provides a detailed characterization of IRIS photometric performance and assesses the accuracy of PSF-Reconstruction algorithms in simulated observational conditions.

Findings

Photometric precision varies with instrumental noise levels.

Reconstructed PSFs can effectively recover photometric accuracy.

Anisoplanatic PSF variations significantly impact photometric measurements.

Abstract

The InfraRed Imaging Spectrograph (IRIS) is a first-light instrument for the Thirty Meter Telescope (TMT) that will be used to sample the corrected adaptive optics field by the Narrow-Field Infrared Adaptive Optics System (NFIRAOS) with a near-infrared (0.8 - 2.4 $\mu$m) imaging camera and integral field spectrograph. To better understand IRIS science specifications we use the IRIS data simulator to characterize relative photometric precision and accuracy across the IRIS imaging camera 34"x34" field of view. Because the Point Spread Function (PSF) varies due to the effects of anisoplanatism, we use the Anisoplanatic and Instrumental Reconstruction of Off-axis PSFs for AO (AIROPA) software package to conduct photometric measurements on simulated frames using PSF-fitting as the PSF varies in single-source, binary, and crowded field use cases. We report photometric performance of the imaging camera as a function of the instrumental noise properties including dark current and read noise. Using the same methods, we conduct comparisons of photometric performance with reconstructed PSFs, in order to test the veracity of the current PSF-Reconstruction algorithms for IRIS/TMT.