The data took almost 10 years to obtain, and provide the most accurate peculiar velocities to date. In three new papers, Dressler and his colleagues John Tonry of the University of Hawaii, John Blakeslee of Caltech, and Ed Ajhar of the National Optical Astronomy Observatories confirm the existence of the Great Attractor. The higher resolution and sensitivity of these new dark-matter maps will allow a much better determination of the extent to which the galaxy distribution traces the dark matter. This information is crucial to interpreting the large-scale structure of the universe as mapped by galaxies, and to understanding the role of dark matter in galaxy formation. Another theme of Dressler's research involves the question of how galaxies formed and evolved over cosmic time.
Astronomers have the unique ability to look back in time as they look far out into space.
With their colleagues, Dressler and Gus Oemler have been using large ground-based telescopes and the Hubble Space Telescope to observe distant galaxies to determine their properties at earlier times. Among the conclusions of this work is that bursts of star formation were much more common in galaxies at that epoch, in contrast to the steadier star-formation rate characteristic of galaxies today. Additionally, the scientists found that because these starbursts were often shrouded by dust, their importance had been underestimated in earlier work. The specific mechanisms responsible for this change remain elusive and are still under study by the group. When mated with the new Magellan I telescope, this instrumentation will open new territory in the high-redshift universe for Dressler and colleagues to study the evolution of galaxies with lookback time.