High angular resolution imaging with stellar intensity interferometry using air Cherenkov telescope arrays

TL;DR

This paper demonstrates the potential of stellar intensity interferometry with air Cherenkov telescope arrays for high-resolution stellar imaging, overcoming phase loss issues with novel reconstruction algorithms.

Contribution

It introduces a Cauchy-Riemann based phase reconstruction algorithm for intensity interferometry images, enabling model-independent stellar imaging with simulated data.

Findings

Bright star diameters reconstructed with a few percent uncertainty

Complex stellar images are accurately reconstructed

Using a forward algorithm improves image quality

Abstract

Optical stellar intensity interferometry with air Cherenkov telescope arrays, composed of nearly 100 telescopes, will provide means to measure fundamental stellar parameters and also open the possibility of model-independent imaging. In addition to sensitivity issues, a main limitation of image recovery in intensity interferometry is the loss of phase of the complex degree of coherence during the measurement process. Nevertheless, several model-independent phase reconstruction techniques have been developed. Here we implement a Cauchy-Riemann based algorithm to recover images from simulated data. For bright stars (m_v~6) and exposure times of a few hours, we find that scale features such as diameters, oblateness and overall shapes are reconstructed with uncertainties of a few percent. More complex images are also well reconstructed with high degrees of correlation with the pristine image. Results are further improved by using a forward algorithm.