Observations of Time Delays in Gravitational Lenses from Intensity Fluctuations: The Coherence Function

Abstract

Measurements of the spectrum of the fluctuations of the output current of the quadratic detector of a telescope can be used to find unresolved astronomical gravitational lenses and determine time delays between their image components. These time delays can be used for astronomical studies. The spatial correlation coefficient of a source is an important parameter that quantifies the loss of contrast, caused by the extendedness of the source, in the spectral modulation of the intensity fluctuations. This work shows that the correlation coefficient must not be evaluated at the frequency of observation, but must instead be evaluated at the much lower beat frequencies of the spectrum of the fluctuations. This opens up a powerful novel technique to find unresolved gravitational lenses and to study the lensing event and the source.

arXiv commentNovel powerful technique to study gravitational lenses. Accepted in Monthly Notices of the Royal Astronomical Society

References in corpus (1)

• Detection of Gravitational Lenses and Measurement of Time Delays from Classical Electromagnetic Radiation Fluctuations

Cited by in corpus (10)

• On the intensity interferometry and the second-order correlation function $g^{(2)}$ in astrophysics
• Intensity interferometry with more than two detectors?
• Strongly lensed supernovae as a self-sufficient probe of the distance duality relation
• Finding Singularities in Gravitational Lensing
• A Novel Technique to Observe Rapidly Pulsating Objects Using Spectral Wave-Interaction Effects
• Exotic Image Formation in Strong Gravitational Lensing by Clusters of Galaxies. I: Cross-Section
• A Novel Type of Very Long Baseline Astronomical Intensity Interferometer
• Observing Gravitational Lenses from Intensity Fluctuations: Experimental Validation of the Technique
• Very long baseline interferometry and observations of gravitational lenses using intensity fluctuations: an analysis based on intensity autocorrelation
• Microlensing and Photon Bunching: The impact of decoherence