January 13, 2005, Santa Cruz, CA--For the first time, astronomers have been able to combine the deepest optical images of the universe, obtained by the Hubble Space Telescope, with equally sharp images in the near-infrared part of the spectrum using a sophisticated new laser guide star system for adaptive optics at the W. M. Keck Observatory in Hawaii. The new observations, presented at the American Astronomical Society (AAS) meeting in San Diego this week, reveal unprecedented details of colliding galaxies with massive black holes at their cores, seen at a distance of around 5 billion light-years.
Observing distant galaxies in the infrared range reveals older populations of stars than can be seen at optical wavelengths, and infrared light also penetrates clouds of interstellar dust more readily than optical light. The new infrared images of distant galaxies were obtained by a team of researchers from the University of California, Santa Cruz (UCSC), the University of California-Los Angeles (UCLA), and the Keck Observatory. Jason Melbourne, a graduate student at UC Santa Cruz and lead author of the study, said the initial findings include some surprises and that researchers will continue to analyze the data in the weeks to come.
"This is very exciting, because we have never been able to achieve this level of spatial resolution in the infrared before," Melbourne said.
In addition to Melbourne, the research team, led by David Koo of UCSC and James Larkin of UCLA, includes Jennifer Lotz, Claire Max, and Jerry Nelson at UCSC; Shelley Wright and Matthew Barczys at UCLA; and Antonin H. Bouchez, Jason Chin, Scott Hartman, Erik Johansson, Robert Lafon, David Le Mignant, Paul J. Stomski, Douglas Summers, Marcos A. van Dam, and Peter L. Wizinowich at Keck Observatory.
"For the first time now in these deepest images of the universe we can cover all wavelengths of light from the optical to the infrared with the same level of spatial resolution, which allows us to observe detailed substructures in distant galaxies and study their constituent stars with a precision we couldn't possibly obtain otherwise," said Koo, a professor of astronomy and astrophysics at UCSC.