My dissertation work at Brown University, as a member of the Observational Cosmology and Weak Lensing group, with Professor Ian Dell'Antonio, involves weak lensing by galaxy clusters. We specialize in astrophysics which probes the expansion of the universe and the structure of matter on the largest scales.


Gravitational lensing utilizes the fact that enourmous unseen conglomerations of matter (spanning millions of parsecs) bend light around them, distorting the appearence of galaxies behind the cluster. Statistical analysis of the overall distortion pattern may be used to reveal the hidden mass. Weak lensing observes the curvature of space-time directly, providing a measurement of cluster qualities independent of dynamical considerations. These techniques are pushing us towards an ever clearer understanding of the distribution of dark matter and the effect of dark energy on the expanding universe.

My most recent work, and the subject of my PhD, is an ambitiously large analysis of imaging from the 8-meter Subaru Telescope in Hawai'i—a project involving reducing a huge amount of raw data into lensing-quality form, correcting for instrumental and observational effects to reconstruct true galaxy shapes, and finally estimating cluster masses by analyzing the overall background galaxy distortions. To do this, I constructed a robust & flexible image-reduction pipeline and sifted through thousands of exposures to select out and combine only the highest-quality data. In addition to this cluster detection approach, I refined observational techniques for measuring cluster masses based on NFW models of cluster masses.

Public Outreach and Teaching

I have also been quite active in outreach efforts in the Providence area, working with Brown's Ladd Observatory, Roger Williams Museum of Natural History, and MLK Elementary School to promote science literacy. I've also taught for Brown Summer High School, Summer@Brown, and hosted dozens of solar observing events for local students. These efforts were undertaken as an NSF GK-12 STEM Education Fellow and as a NASA RI Space Grant Fellow. I strongly believe that fostering our understanding of the cosmos and the world around us is a vital public good.

Ryan Michney, PhD

Barus & Holley Building
Room 717