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Fate and Stars


June 20, 2007

Rogier Windhorst has spent his entire career thinking big. He has to. He is an astrophysicist. He uses the most advanced telescope systems ever developed to peer into deep space, and essentially back in time.

Fun stuff. But what’s the goal behind all this thinking and looking? Simple. Figure out how and why the universe developed the way it did.

Work on this grand scale has given Windhorst a wonderful long-term perspective. But, even he didn’t see what would result from a somewhat innocuous meeting with a medical researcher on Arizona State University’s Tempe campus in early 2000.

Windhorst is a Regents’ professor of physics and astronomy with ASU’s School of Earth and Space Exploration. During the meeting, he realized that a computer software technology he regularly uses to sort out the oldest galaxies might actually have several important applications for saving lives here on Earth right now.

At the 2000 meeting, Windhorst met medical researcher Richard Herman, a physician from Phoenix-based Banner Health. At first glance the pairing might appear odd. One researcher was interested in looking at objects on a galactic scale; the other was focused on objects that appear on a microscopic scale. Was there a way to mesh their individual interests and projects?

Windhorst and Herman moved on from those initial exploratory discussions to early tests. Now there are ongoing clinical trials where the Windhorst’s software package is used to help detect the early onset of Type-II diabetes in children. The ASU scientist now is exploring its possible use in cancer detection applications.

Windhorst and his group modified a computer software package that they had used since the 1990’s to help discern images sent back from the Hubble Space Telescope. The orbiting telescope can look back 95 percent of the way in time to the “dawn of the cosmos.” Windhorst says that he and his colleagues use the software to pinpoint any galaxy that may be crowded together with many other galaxies.

“In astronomy, we are looking at galaxies that are so far away in deep space that there is some overlap of objects,” Windhorst explains. “You cannot see the forest for the trees.”

“It’s like taking a picture of a football stadium filled with 100,000 people and trying to find just one person,” he says. “The software does a ‘de-blending’ of objects where there may be overlapping. It isolates those objects and counts them very accurately.”

Dr. Herman is director of the Clinical Neurobiology & Bioengineering Research Center at Banner Good Samaritan Medical Center in Phoenix. He needed something that could help him count C-fibers in skin biopsies. By counting C-fibers in biopsies, the doctor learned that he could detect the onset of Type-II diabetes in children at a very early stage.

“Dr. Herman was bemoaning how hard it was to count all of the fibers to a high degree of accuracy,” Windhorst recalls. “It was a solved problem for us. We counted galaxies that same basic way. We asked Herman to give us an image. We tinkered with it to see if we could apply our software to his problem. It took some effort, but it does work.”

Intellectually, Windhorst says he lives for these unexpected twists and turns. He finds them in his research, which focuses on cosmological questions like the dawn of galaxies and the structure and activity of black holes. They also occur as part of his teaching with both ASU graduate and undergraduate students at Arizona State. He says it is the quest to confront the unknown, figure it out and explain it that gives him great satisfaction.

“I really like to make the best use of myself by exploring new things and getting my students involved in new areas,” he says.

The ASU scientist’s research has significantly added to the current understanding of the universe and the reasons why it is the way it is. He has been one of the most consistently funded users of the Hubble Space Telescope. Using HST images allows Windhorst to explore some of the most basic and fundamental questions about the structure of the universe. He also is actively involved in upgrades to the Hubble and is part of the science team working to develop its successor. The James Webb Space Telescope is scheduled for launch in 2013.

Galaxies and Black Holes
Windhorst knows about “First Light.” His research has led to new understanding of how the universe first lit up with observable stars and galaxies. The process ended the so-called re-ionization epoch of hydrogen, which he says means we live in a “refried universe” today. One of his students found that this re-ionization process was caused by an early epoch of galaxy formation.

Windhorst also studies black holes. The bigger the better. He says that black holes are among the most curious entities found in the universe. Black holes are so dense that nothing, not even light, can escape them. The ASU scientist’s research is designed to determine how massive black holes became so large. Giant black holes are found at the center of many galaxies, including our own Milky Way.

The work is based on some of the deepest views of the universe. His findings provided compelling evidence those monster black holes in the centers of galaxies were not born. They grew big over time through repeated mergers on a galactic scale. Large galaxies essentially eat or incorporate the mass of smaller galaxies.

The topic can be complex, dense with jargon, and mind bending. But Windhorst explains it in very common terms.

“A black hole’s typical mealtime lasts a few dozen million years,” he says. “This is equivalent to black holes spending no more than 15 minutes per day eating all their food – a veritable fast food diet.”

Windhorst’s current work involves looking at another peculiarity of the black holes. They appear to exist at the center of every galaxy, young and ancient.

“Black holes are not always active, they are not always dining on nearby stars,” Windhorst says. “You only see it as an active nucleus in 2 to 6 percent of the cases. That is the caveat. You have to look very carefully to see the signs of the faint and feasting black hole.”

Typically, Windhorst says that detectable black holes are present in middle-aged galaxies. But now he and his ASU students are seeing black holes in faint galaxies that date back to the first billion years of the universe.

For astronomers, stars that existed 300 million to 400 million years after the beginning of the universe are known as Population III stars.

Windhorst’s question: “How do you go from leftover black holes of the first generation of Population III stars to a billion-solar-mass black hole about 500 million to 1 billion years later? That is tremendous growth. We have no idea how it did that,” Windhorst says.

Focus on students
Windhorst puts his graduate students front and center in research projects and always notes their involvement and accomplishments. His graduate students have found homes at Caltech and Carnegie Observatories, both in Pasadena, Calif., and Johns Hopkins University in Baltimore. Russell Ryan is a current student. Ryan plays an integral role in the development of software that may improve cancer detection techniques.

“I take great pride in my students doing well,” Windhorst says with emphasis.

The ASU scientist teaches his undergraduate classes with equal vigor. Astronomy is a field that can quickly captivate the imagination or just as quickly lose a student in minutiae. Windhorst says that a few interesting twists can keep most any student actively involved.

He teaches two introductory classes. One is focused on the planets of our solar system. The other on stars and galaxies. Hundreds of students take the courses to fulfill their science requirements. Windhorst always includes an end-of-semester project that challenges each of his students to prove that they have mastered one thing in their universe – the scientific method.

“On the final day of class, we have a great debate on whether or not ET exists,” Windhorst says. “You can argue either way, and there is only one rule for the debate. You must use the scientific method. The student is not allowed to say: ‘I believe in ET because I was beamed up and they did experiments on me,” he laughs.

Within that constraint, he says the non-science majors have shown a wide breath and intellectual depth to many of their arguments. They debate about, among other things, advanced societies, space-faring beings, methods of interplanetary communication, the physical abilities to traverse huge amounts of space in relatively short periods of time, and societal sustainability.

One argument that popped up in a class focused on the most likely way to communicate with people of other planets – which would be through radio signals and require development of radio telescopes. The argument touched on how radio telescopes were developed on Earth and our society’s flirtations with self destruction.

The students noted the physical constraints of radio signals and put a 100-year limit on the lifetime of an advanced society that develops such technology and before its possible self destruction. Windhorst says the students argued that “ET’s could be like fireflies passing in the night. They may not see each other before obtaining the technology to destroy themselves.”

The debate along those lines can be argued in a fairly scientific way.” It serves as another good reason not to have nuclear wars,” Windhorst adds. “We want ET to see us!”

Editor's note: This article originally appeared in ASU Research Magazine. Visit Research.