University of Hawaii
Institute for Astronomy

J. Patrick Henry

Professor and Astronomer
Ph.D., University of California, Berkeley, 1974
henry@ifa.hawaii.edu

Cosmology

Research Description

With my collaborators, I investigate the origin and evolution of large-scale structure in the universe as elucidated by clusters of galaxies. We construct samples of distant clusters of galaxies identified by their X-ray emission. Such samples should be less prone to a bias that may exist in optically selected catalogs. This work requires a synthesis of space and ground-based observations. In recent years we have constrained the dark matter and dark energy density parameters of the universe from the cluster temperature function at moderate redshift.

I am also interested in physical processes occuring in clusters of galaxies. We have made temperature, pressure and entropy maps of bright clusters of galaxies. We have also made some of the first high spectral resolution absorption measurements against background AGNs that show the velocity distribution of warm gas associated with the cluster.

My collaborators include X-ray astronomers around the world. I am an invited member of the Science Working Group for the upcoming Japanese observatory ASTRO-E2, scheduled to be launched in 2005. I work closely with the X-ray astronomy group at the Max Planck Institute in Garching Germany, most recently as the reciepient of a Humboldt Senior Research Prize.