2012/09/06 by Paul D. Nuñez, Nunez, Paul D.
Physics and Astronomy · Engineering · #Stellar, planetary, and galactic studies #Adaptive optics and wavefront sensing #Astronomical Observations and Instrumentation
paper · pdf · doi:10.48550/arxiv.1209.1205
Most neighboring stars are still detected as point sources and are beyond the\nangular resolution reach of current observatories. Methods to improve our\nunderstanding of stars at high angular resolution are investigated. Air\nCherenkov telescopes (ACTs), primarily used for Gamma-ray astronomy, enable us\nto increase our understanding of the circumstellar environment of a particular\nsystem. When used as optical intensity interferometers, future ACT arrays will\nallow us to detect stars as extended objects and image their surfaces at high\nangular resolution.\n Optical stellar intensity interferometry (SII) with ACT arrays, composed of\nnearly 100 telescopes, will provide means to measure fundamental stellar\nparameters and also open the possibility of model-independent imaging. A data\nanalysis algorithm is developed and permits the reconstruction of high angular\nresolution images from simulated SII data. The capabilities and limitations of\nfuture ACT arrays used for high angular resolution imaging are investigated via\nMonte-Carlo simulations. Simple stellar objects as well as stellar surfaces\nwith localized hot or cool regions can be accurately imaged.\n Finally, experimental efforts to measure intensity correlations are\nexpounded. The functionality of analog and digital correlators is demonstrated.\nIntensity correlations have been measured for a simulated star emitting\npseudo-thermal light, resulting in angular diameter measurements. The StarBase\nobservatory, consisting of a pair of 3 m telescopes separated by 23 m, is\ndescribed.\n