Optical long baseline intensity interferometry: prospects for stellar physics

Abstract

More than sixty years after the first intensity correlation experiments by Hanbury Brown and Twiss, there is renewed interest for intensity interferometry techniques for high angular resolution studies of celestial sources. We report on a successful attempt to measure the bunching peak in the intensity correlation function for bright stellar sources with 1 meter telescopes (I2C project). We propose further improvements of our preliminary experiments of spatial interferometry between two 1 m telescopes, and discuss the possibility to export our method to existing large arrays of telescopes.Keywords Temporal and spatial photon bunching · micro-arc-second interferometry · in the optical wavelengths

Intensity interferometry of P Cygni in the H α emission line: towards distance calibration of LBV supergiant stars

“…In this context our group started a number of pilot experiments in 2016 using two modest 1 m size optical telescopes. After the successful observations of temporal and spatial bunching on a few bright stars at 780 nm [14,15,26,43], we decided to observe emission-line stars. The LBV star P Cyg is a very good candidate due to its strong H and He emission lines.…”

Observations with the Southern Connecticut Stellar Interferometer. I. Instrument Description and First Results

“…Alternatively, significantly fainter limiting magnitudes are now possible with telescopes that are comparable in size to the Narrabri instrument. Several groups have built new intensity interferometers and reported successful correlation measurements in recent years, including Rivet et al (2018Rivet et al ( , 2020; Acciari et al (2020); Abeysekara et al (2020); and Zampieri et al (2021). The intrinsic timing resolution of these instruments spans a range from roughly 400 ps to 2.5 ns and they use telescopes with diameters of 1 to 17 m; in the case of larger telescopes (Acciari et al 2020;Abeysekara et al 2020), these are so-called "light-bucket" telescopes, which do not have high optical resolution, and as a consequence, detectors with a larger active area must be used to collect the light, generally photomultiplier tubes.…”

Generation of N00N-like interferences with two thermal light sources

“…The algorithms presented in this paper could be of interest for any lens-less far-field imaging scheme, e.g., in astronomy where recent investigations of HBT measurements revived the field of intensity interferometry for the observation of distant stars [51][52][53][54][55][56][57][58]. In particular, the possibility to increase the resolution in intensity interferometry by use of higher-order correlation measurements with detectors at specific positions might be of interest in this context.…”