Speaker
Description
Abstract: Over the past decade, significant advances in instrumentation technology have led to new astronomical capabilities and increased sensitivity in the emerging field of Stellar Intensity Interferometry (SII). The rapid emergence of SII has been made possible by the convergence of the availability of inexpensive GHz sampling digitizers, White Rabbit sub-nsec clock distribution over km baselines, massive (100TB+) high-speed disk array, and affordable digital correlators using FPGAs, multithreaded CPA, and GPU. The compactification of the size and power requirements of these technologies has enabled SII deployment on arrays of large Imaging Atmospheric Cherenkov Telescopes (IACTs), such as VERITAS, MAGIC, HESS, and CTAO-LST. This combination has created a new ultra-high angular resolution capability in astronomy at a fraction of the cost of a traditional Michelson interferometer.
The era of modern SII was heralded by the first demonstrated measurements of angular diameters of round stars in 2019, using the VERITAS Array of IACTs. It has rapidly progressed to the measurement of elongated stellar envelopes of fast-rotating stars and a recent capability to resolve aspects of binary stellar systems. In this talk, I will review the rapid emergence of the field of modern SII, including seminal discoveries and emerging techniques. I will review the historical and recent progress made by multiple international observatories and describe emerging science cases as SII technology develops. In closing, I will describe some new results from the VERITAS Northern Sky SII Survey, illustrating the rapidly emerging scientific capabilities of the field of SII.
