Jon Zwart

Jonathan Zwart

SARAO Postdoc

Jon holds a SKA Research Fellowship jointly at UWC and UCT. He completed his PhD in observational cosmology through radio astronomy in 2007, in particular using radio-continuum studies of the Cosmic Microw​​ave Background to search for clusters of galaxies using the so-called Sunyaev-Zel’dovich effect. After a spell at Columbia University in New York working on CMB polarization to probe the very early, inflationary phase of the Universe, he moved to South Africa to begin preparatory analyses for radio-continuum surveys with MeerKAT and eventually SKA.​ ​Jon now specializes in statistical (especially Bayesian) analyses of interferometric data, whether in radio maps or directly in the ‘visibility’ domain in which they are taken. He models the noise properties of the data – the part other astronomers throw away – in order to extract the maximum amount of information possible. Jon is as comfortable building a radio telescope as he is taking and analysing data from it, but one thing for sure is that he is always on the hunt for novel applications of Bayes’ theorem, and, recently, machine learning. He is also co-author of the popular astronomy book, Practical Astronomy with your Calculator or Spreadsheet (


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