Ian Sullivan

My background in experimental astrophysics has taught me that the best approach to making a major breakthrough is to develop new instruments and invent new technologies that open up possibilities for research. As a Research Scientist at the University of Washington, I have taken that philosophy to the field of radio astronomy, where I have led the development of a new end-to-end imaging algorithm for radio telescopes called Fast Holographic Deconvolution (FHD). With FHD, we have designed an imaging and deconvolution pipeline to detect the first stars and galaxies to ever form in the universe through the power spectrum of the faint diffuse radio background, but it has also opened up exciting new research opportunities to study the nearby universe, from the diffuse structure of the Milky Way to nebulae and surveys of radio galaxies.

As a PhD student at Caltech, I approached the problem of detecting the earliest stars from a different angle. While the detectable signal at radio wavelengths is emission from neutral Hydrogen outside the pockets where the first stars formed, the ultraviolet-peaked radiation from those first stars will have been redshifted to the near-infrared today and should be detectable in the power spectrum of the infrared background. To this aim, we designed and built the Cosmic Infrared Background Experiment (CIBER), a suite of two wide-field infrared cameras and two spectrometers on board a NASA sounding rocket. As the senior graduate student, I was actively involved in every aspect of the project, from initial design and fabrication, through calibration and preparation for flight, to writing the full pipeline for analysis of flight data from the imagers. During that time, I worked with deep survey data from the Hubble and Spitzer space telescopes to refine the analysis techniques, and published results that challenged the reported detection of a signal from the first stars in the infrared background from those data.