Speaker
Description
We investigate the possibility of detecting stellar eclipses of millimeter radio cores in nearby radio-loud active galactic nuclei. At millimeter wavelengths, the compact radio core can be partially occulted by large evolved stars orbiting the central supermassive black hole within a dense nuclear star cluster. We show that stars with radii >= 500 Rsun can produce the eclipses with relative depths of up to ~10%, with typical durations of about 10 days and recurrence timescales of at least a decade. The eclipse profiles depend strongly on observing frequency, becoming broader and shallower at lower frequencies and deeper and narrower at higher frequencies. Although such events are expected to be rare, their detection would provide a novel probe of supermassive black hole masses and of the stellar populations in nuclear star clusters.