Eternal life of stardust portrayed in Spitzer image
UNIVERSITY OF ARIZONA NEWS RELEASE
Posted: September 1, 2006
"We can use this amazing map to really start to understand in detail how a galaxy evolves," said Karl Gordon of the University of Arizona Steward Observatory. Gordon heads the UA group who processed 600,000 images that Spitzer's Multiband Imaging Photometer (MIPS) took of the Large Magellanic Cloud.
The Large Magellanic Cloud, a satellite galaxy of our Milky Way about 160,000 light years away, is an ideal astrophysical laboratory for studying the lifecycle of galaxies.
Using Spitzer's unprecedented sensitivity across a spectrum of infrared wavelengths, "We now can study some details in another galaxy that so far we've been able to study only in our own galaxy," Gordon said.
Spitzer scientists combined some of the MIPS images with others taken by the Infrared Array Camera (IRAC), a Spitzer instrument that takes images at shorter infrared wavelengths than MIPS does. The result is a composite picture of 300,000 images of the Large Magellanic Cloud, a picture that shows everything from hot stars to cold dust between the stars, or the interstellar medium.
"What's exciting and significant is that our images go really deep in the galaxy, deep enough to get a life cycle of the interstellar medium, a life cycle of dust. We see young stars which consume dust as they form in dusty molecular clouds and old stars which are ejecting dust back into the interstellar medium.
"We can now test sophisticated theories about how stars form, how they evolve, what the different populations are, and how important they are in a global galaxy environment," Gordon said. "One of the strengths of this is not just that we've measured a small piece of the galaxy, but we've measured almost the entire galaxy in deep, sharp detail."
The survey of the Large Magellanic Cloud is among 19 key "Legacy" projects undertaken by NASA's Spitzer Space Telescope, which was launched August 2003. The project is headed by Margaret Meixner of the Space Telescope Science Institute in Baltimore. Others from the UA Steward Observatory who are reporting this research in the Astronomical Journal are Charles W. Engelbracht, Bi-Qing For, Karl Misselt, Jason Harris, Douglas Kelly, Pablo Perez-Gonzalez and Dennis Zaritsky.
Spitzer's MIPS instruments was developed at The University of Arizona by a team headed by Regents' Professor George Rieke.
The Jet Propulsion Laboratory manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech. Caltech manages JPL for NASA.