Images · Extragalactic Astronomy

Extragalactic Astronomy

Nearby galaxies, distant galaxies and quasars, and strong gravitational lenses: topics where sharper, better-understood images make a difference.

In brief

Much of extragalactic astronomy is measured from images: the resolved stars of nearby galaxies, the faint host galaxies of distant quasars, the arcs of strongly lensed galaxies, and the photometry behind the distance ladder. In each case, the results depend on how well the point spread function, the sampling and the noise of the images are understood. Images from the Hubble, Webb and Euclid telescopes, like Roman's, are often undersampled in some of their bands, which is the problem my work on image reconstruction addresses.

Thousands of galaxies of many shapes and colors; the bright galaxies of a foreground cluster are surrounded by thin, stretched arcs of more distant galaxies. — Webb's First Deep Field: the galaxy cluster SMACS 0723, whose mass bends the light of more distant galaxies into arcs, among thousands of galaxies. Credit: NASA, ESA, CSA, and STScI (ESA/Webb, CC BY 4.0).

How I can contribute

These topics are new to me as a researcher, and I am glad to contribute my image processing expertise to them: reconstructing images with controlled point spread functions (Effortless), understanding their noise and systematics, and checking how image processing affects the measurements that follow. If you work on one of these topics and your images could benefit, I would be happy to talk.