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Studying galaxies is something usually reserved for trained astronomers and graduate students at universities with noted observatories.

But Lafayette is giving physics majors Adeel Altaf ’06 (Karachi, Pakistan) and Marquis Scholar Josh Goldstein ’07 (Hockessin, Del.) the opportunity to use the most advanced radio telescope in the world to study a galaxy 20 million light years from Earth.

The two are studying NGC 2903, a neighboring galaxy to the Milky Way, mapping its hydrogen clouds.

“We’re doing observations from the Arecibo telescope, then using that data, we convert it to images of the galaxy and analyze them to see what sort of structures there are inside,” reports Altaf. “We also have to clean up the images to get a better idea of the location of the hydrogen clouds.”

“We have a software program that cleans up the images,” adds Goldstein, “so we spent a lot of time programming to get rid of the diffraction and eliminate this ‘noise’ and radio interference from the images.”

The two are mentored by Lyle Hoffman, professor and head of physics. Hoffman is part of a 43-member international team of astronomers and scientists from 29 institutions around the world who are using the Arecibo radio telescope in Puerto Rico to examine hydrogen gas clouds in galaxies, seeking to learn more about how galaxies form and better understand their composition.

As part of his research, Hoffman is examining the NGC 2903 galaxy with Judith Irwin of Queens University Ontario to explore hydrogen gas formations at the galaxy’s edge, trying to get details of how the gas trails off at the edge of galaxies.

Altaf and Goldstein are helping Hoffman create a map of NGC 2903, one that will be of greater sensitivity than has been produced of any galaxy, in order to study its hydrogen gas formations. The galaxy is not only close to our own, it also has a mass comparable to the Milky Way, making it particularly attractive for study.

The students are collaborating with Hoffman as part of Lafayette’s distinctive EXCEL Scholars program, in which students assist faculty with research while earning a stipend. The program has helped make Lafayette a national leader in undergraduate research. Many of the more than 160 students who participate in EXCEL each year go on to publish papers in scholarly journals and/or present their research at conferences.

“We are studying hydrogen clouds and trying to map them because we want to see how much mass there is,” says Altaf. “We can account for the mass of stars and gas clouds, but when we look at the rotation of the galaxies, there is mass that does not correspond to the mass we are seeing. So there is hidden matter around the galaxies; the hydrogen might be part of that. How the hydrogen is spread throughout the galaxy might give us an idea of how much mass there is besides that which we are seeing.”

“A galaxy has a rotation curve,” explains Goldstein, who is pursuing a second degree in mathematics. “What you expect to see is that on the outside of the rotation things rotate slower. But it turns out that the rotation curve is uniform – so there has to be some sort of mass on the outer edge of the galaxy. We’re looking at that outer edge for evidence of this dark matter.”

“Dark matter” is the unexplained matter in the universe, according to Hoffman, and though scientists don’t know what it is, they can simulate its behavior under gravity. As hydrogen gas is the most common element in the universe, scientists expect to see hydrogen in what they call “dark matter halos.” If the density of the matter is high enough, it forms stars.

A radio telescope enables astronomers to unravel puzzles the universe poses that couldn’t be explored otherwise, collecting the radio waves emitted by galaxies, erupting stars, clouds of gas, pulsars, and quasars. Because radio waves have a lower energy and the longest wavelength on the magnetic spectrum, they can pass through the dust clouds of galaxies, as well as the clouds of Earth, giving Altaf, Goldstein, and Hoffman a chance to map the hydrogen clouds of NGC 2903 and what lies behind them.

The Arecibo telescope is a scientific tour de force, its 305-meter dish and seven receivers, location near the equator, and natural topography giving researchers a chance to map one-fourth of the sky. Its majestic presence has also captured Hollywood’s attention – the ending fight scene in the James Bond movie Goldeneye and much of Contact, starring Jodie Foster, were filmed at Arecibo.

Using such technology has given the students an invaluable lesson in astronomy and the tools of the profession. They controlled the telescope from Union College during a two-week workshop they attended and spent a week on-site at the observatory.

“I never would have been able to use the Arecibo telescope or the software programs or get the chance to study the sky at another undergraduate institution,” says Altaf. “The opportunity to look up at the sky, not just with the naked eye but to look at things light years away — it puts what you study in class into perspective. I actually saw things like Newton’s laws working.”

“This project really has introduced me to what research is,” says Goldstein. “It is more intellectually challenging than classroom work because we are discovering new things. It’s not something you can just study and learn about. It is more independent than class work because I have to come up with methods, devise my own program of what I want to get done.”

Hoffman, who has been researching the galaxies for more than 25 years, can put their experience in perspective.

“Radio astronomy is unusual for an undergraduate; normally one wouldn’t get this experience until graduate school in astronomy. So the chance to work with any radio telescope is significant,” says the 23-year veteran of the Lafayette faculty.

Altaf and Goldstein appreciate the benefits of using software that is state-of-the-art in the field.

“They’re using primarily software called AIPS++ that was written by the National Radio Astronomy Observatory, meant to be a platform for use on essentially all radio telescopes,” says Hoffman. “It’s very high-powered software. They’re getting a lot of experience with dealing with very complex software systems, very complex data systems, and it’s useful anytime you’re trying to make maps of the sky of radio images. So they’ve been using that to try to combine the data we get from Arecibo into a final map.”

“I had a sense that they would be diligent workers and they have been. What I didn’t anticipate was that they would form a very effective team. The two working together I would say are stronger than the two of them would have been separately,” adds Hoffman.

Altaf originally intended to be an electrical and computer engineering major, but the awe of astronomy and physics changed his mind, like the awe of studying NGC 2903, which is 20 million light years from Earth. The Milky Way Galaxy is 100,000 light years in diameter, but NGC 2903 still is relatively close when considering that the observable universe is 30 billion light years in diameter.

“You look up and you see all those stars, and you’re thinking ‘Where is all this coming from? Why? How?’ Those kinds of questions – that’s what drives you,” says Altaf. “Once you get into it, you’re doing calculations. But once in a while I stand back and look at the whole picture and say, ‘wow!’”

Altaf is working on an honors thesis that stems from this research project. He is a member of the Pi Mu Epsilon mathematics honor society and International Students Association, serves as treasurer of Physics Club, and is a resident adviser in Watson Hall. Altaf also was president of Cricket Club and a peer tutor. He is a graduate of St. Patrick’s High School.

Goldstein is an intramural croquet champion, an active participant in the Math, Physics, and Japanese clubs, and a member of the Dry Surfers living group. He is a graduate of Sanford School.

As a national leader in undergraduate research, Lafayette sends one of the largest contingents to the National Conference on Undergraduate Research each year. Thirty-nine students were accepted to present their research at this year’s conference.

Categorized in: Academic News