Astrometry with Extended-Path Intensity Correlation

TL;DR

The paper proposes an innovative method called Extended-Path Intensity Correlation (EPIC) that enhances intensity interferometry for high-precision ground-based astrometry over larger fields of view, enabling new astronomical measurements.

Contribution

Introduction of EPIC, a novel interferometric technique with adjustable path extension, to achieve microarcsecond astrometry over several arcseconds field of view.

Findings

EPIC can detect astrometric wobble of Earth-like planets.

EPIC extends the field of view for intensity interferometry.

Potential to revolutionize high-precision astronomical observations.

Abstract

Intensity interferometry -- the correlation of spatially separated light intensities -- has historically been an important tool for precision optical astronomical observations. However, due to the extremely narrow field of view, its scope has been limited to studies of the morphology of very bright emission regions, primarily determinations of angular diameters of nearby hot stars. We propose adding an adjustable path extension into the detector optics which creates a primary interference fringe for widely separated sources, allowing maximum source separations parametrically larger than the angular resolution. This Extended-Path Intensity Correlator (EPIC), augmented with advances in single-photon detectors and spectroscopic gratings, would enable ground-based astrometry at microarcsecond-level precision in a field of view as large as several arcseconds. EPIC has the potential to revolutionize astrophysical and cosmological observations requiring high-precision differential astrometry on sources of high surface brightness. We outline how EPIC can be employed to detect the astrometric wobble of Earth-like planets around Sun-like stars at tens to hundreds of parsecs, and expect that EPIC's larger field of view will expand the power of intensity interferometry to a broad range of astronomical applications.