Stellar Intensity Interferometry: Astrophysical targets for sub-milliarcsecond imaging

TL;DR

Intensity interferometry with kilometric Cherenkov telescope arrays can achieve sub-milliarcsecond resolution, enabling detailed imaging of hot stars, circumstellar structures, and stellar pulsations with high spatial detail.

Contribution

This paper demonstrates the potential of planned Cherenkov telescope arrays for high-resolution optical astronomy through intensity interferometry, expanding observational capabilities.

Findings

Simulations confirm tens of microarcsecond resolution is feasible.

High-temperature and emission-line sources are optimal for intensity interferometry.

Large Cherenkov arrays can synthesize numerous baselines for detailed stellar imaging.

Abstract

Intensity interferometry permits very long optical baselines and the observation of sub-milliarcsecond structures. Using planned kilometric arrays of air Cherenkov telescopes at short wavelengths, intensity interferometry may increase the spatial resolution achieved in optical astronomy by an order of magnitude, inviting detailed studies of the shapes of rapidly rotating hot stars with structures in their circumstellar disks and winds, or mapping out patterns of nonradial pulsations across stellar surfaces. Signal-to-noise in intensity interferometry favors high-temperature sources and emission-line structures, and is independent of the optical passband, be it a single spectral line or the broad spectral continuum. Prime candidate sources have been identified among classes of bright and hot stars. Observations are simulated for telescope configurations envisioned for large Cherenkov facilities, synthesizing numerous optical baselines in software, confirming that resolutions of tens of microarcseconds are feasible for numerous astrophysical targets.