A Clear View of the Galaxy: Benjamin part of a project aboard NASA's 'Next Great Observatory'
Alumni & Friends, Winter/Spring 2004
Imagine a mountain hiker’s payoff when he reaches a clearing and catches a glimpse of a sprawling vista, a view so sharp and wide that it seems to take in an entire mountain range.
That’s close to what Robert Benjamin hopes to feel at the end of a landmark NASA space telescope project, aptly called Project GLIMPSE. Benjamin, a professor of physics at UW-Whitewater, is part of a team of researchers that will use time on NASA’s Space Infrared Telescope Facility (SIRTF) to piece together the most clear and complete view ever of the Milky Way.
The SIRTF telescope, which was launched in August 2003, is the last installment in NASA’s “Next Great Observatory” series that is producing new ways to study the universe. This telescope’s hallmark is the use of infrared light, which is capable of filtering through the shroud of dust that obscures much of the Milky Way.
Allotted more than 400 hours of time on the five-year orbiting telescope, Benjamin and colleagues hope to get “a clearer view of the galaxy,” peering more closely into the Milky Way’s cataclysmic core and its star formation engines.
“Interstellar dust has blocked out a lot of interesting things,” said Benjamin. “The regions where stars are forming, the central part of the Milky Way, and the regions of other galaxies where you have massive black holes are all obscured. Being able to penetrate through that dust is a big thing scientifically.”
A first test image from SIRTF, released about a month after the launch, demonstrated that the telescope is working properly, said Benjamin, noting that the images will get better as the telescope cools.
“Project GLIMPSE is going to get 80,000 pictures much like that first one,” he said. “It’s like going hiking and taking a photo montage by stringing all the images together. We’re going to produce the most panoramic view of the Milky Way of any of the NASA telescope projects.”
From a scientific standpoint, revealing what’s currently obscured by dust will be the most important goal. The majority of stars in the galaxy have never been seen, he said, primarily because they exist in the foggy center of the Milky Way.
Benjamin said the plan is to map the inner part of the Milky Way but not the absolute center, which is too bright and too crowded with stars to achieve usable images. Benjamin said the project might confirm the widely held theory that the center of the Milky Way has a “stellar ring.” It will also be able to peer into sites of active star formation “and get an idea of how prolific the Milky Way is as a star formation engine.”
The project will also be able to shed a new perspective on one of the Hubble telescope’s most famous images – that of the Eagle Nebulae, or more commonly known as the “Pillars of Creation.” This breathtaking image shows massive columns of dust clouds that obscure the violent process of star formation.
Before the SIRTF opportunity, Benjamin was more interested in the gas and dust around the stars than the stars themselves. He studied a phenomenon called “galactic fountains,” where exploding stars would send gases shooting up and out of the galaxy. Now, SIRTF has him focused on the perplexing physics of star formation.
Benjamin’s work on SIRTF began as a post-doctorate at UW-Madison, where he was involved in “big picture” science planning and modeling.
“It’s really cool to have been involved from the beginning, when we were sitting around a coffee table trying to decide what to do with 400 hours of observing time,” said Benjamin. “We went from getting the time to now being close to collecting this panoramic view of the Milky Way. It’s a pretty neat experience.”
Benjamin plans to present early results from the mission during a public lecture May 7, as part of the ongoing Observatory Lecture Series organized by physics Professor Paul Rybski. – Brian Mattmiller