# PRIME: Psf Reconstruction and Identification for Multiple sources characterization Enhancement. Application to Keck NIRC2 imager

## TL;DR

PRIME is a novel PSF reconstruction method that jointly uses science images and AO control data to improve astrophysical measurements, validated on Keck NIRC2 images with high accuracy in photometry and astrometry.

## Contribution

This paper introduces PRIME, a new PSF reconstruction and identification technique that enhances accuracy by calibrating PSF models directly on scientific images, validated on Keck NIRC2 data.

## Key findings

- Achieves 1% accuracy on Strehl ratio and 3 mas on PSF FWHM.
- Maintains photometry precision below 0.005 mag and astrometry below 100 μas for 14 mag objects.
- Provides accurate PSF calibration for binary and triple star systems.

## Abstract

In order to enhance accuracy of astrophysical estimates obtained on Adaptive-optics (AO) images, such as photometry and astrometry, we investigate a new concept to constrain the Point Spread Function (PSF) model called PSF Reconstruction and Identification for Multi-sources characterization Enhancement (PRIME), that handles jointly the science image and the AO control loop data. We present in this paper the concept of PRIME and validate it on Keck II telescope NIRC2 images. We show that by calibrating the PSF model over the scientific image, PSF reconstruction achieves 1\% and 3 mas of accuracy on respectively the Strehl-ratio and the PSF full width at half maximum. We show on NIRC2 binary images that PRIME is sufficiently robust to noise to retain photometry and astrometry precision below 0.005 mag and 100$\mu$as on a $m_H=$ 14 mag object. Finally, we also validate that PRIME performs a PSF calibration on the triple system Gl569BAB which provides a separation of 66.73$\pm 1.02$ and a differential photometry of 0.538$\pm 0.048$, compared to the reference values obtained with the extracted PSF which are 66.76 mas $\pm$ 0.94 and 0.532 mag $\pm$ 0.041.