University at Buffalo - The State University of New York

Published: January 15, 2004

By DONNA BUDNIEWSKI
Reporter Assistant Editor

Emerging from the center of an active galaxy or a violent cosmological event like the birth of a black hole or the emission of a gamma ray burst may be tiny neutrinos—subatomic particles of interest to scientists because they travel through the universe relatively unaffected by magnetic fields, thus preserving information about their origin.

The Admundsen-Scott South Pole Station served as Michael Stamatikos' home for three weeks in November while he furthered his understanding of neutrinos and their possible connection to gamma ray bursts.
PHOTO: AMANDA PROJECT

An international group of astrophysicists and researchers like Michael Stamatikos, a doctoral student in the UB Department of Physics, believe the best hope of seeing these ghost-like particles is buried under the Antarctic ice—a telescope constructed of 677 optical modules (light sensors that detect the faint blue light emitted when neutrinos collide with other subatomic particles) known as the Antarctic Muon and Neutrino Detector Array (AMANDA). The telescope looks down, through the ice, to the sky in the Northern Hemisphere. The University of Wisconsin at Madison directs the AMANDA project.

Buffalo native Stamatikos traveled to the Admundsen-Scott South Pole Station in November, spending three weeks performing routine maintenance on AMANDA and furthering his understanding of neutrinos and their possible connection to gamma ray bursts, which he says have remained a mystery to scientists some 30 years after they were discovered.

Stepping off the LC-130 Hercules airplane and onto the infinite sheet of snow and ice at the South Pole in minus 50 degrees (Fahrenheit) temperatures was breathtaking and beautiful—just sky and ice, says Stamatikos—and a bit dizzying until he acclimated to the high altitude. He was lucky, too, he points out, that he visited the pole during summer and perpetual sunlight, when winds are relatively calm and temperatures are considered mild.

"The South Pole gets less precipitation than the Sahara desert, making it the driest place on earth, so because of its extreme dryness, it doesn't feel as cold as it sounds—it was actually bearable," says Stamatikos.

Stamatikos (right) and a colleague ride on one of the snowmobiles used to get around at the South Pole. Stamatikos says the extreme dryness of the pole—it gets less precipitation than the Sahara desert—makes the cold bearable.
PHOTO: AMANDA PROJECT

His journey to "the ice," as long-term inhabitants call the South Pole, included a stop-off in New Zealand to gear up for the harsh Antarctic environment before making the eight-hour flight to McMurdo Station on the coast of Antarctica, the jumping off point for most travelers to the pole.

What makes the South Pole an optimal locale to view neutrinos is the bulk, purity and clarity of the ice. The optical modules are sunk into the ice about 1.5 to 2.5 kilometers deep via hot-water drilling and soon will be expanded to one square kilometer over the surface of the ice in a project recently funded by the National Science Foundation to enlarge AMANDA into IceCube, as the more sensitive instrument will be known, says Stamatikos.

"When you look at some of the greatest discoveries that have been made, they've almost always been made accidentally. Someone's looking for one thing and they get something else. Here, we're not totally going into it blind, but if you think about the overall concept of what we're trying to do, we're asking a simple question: What would the universe look like if we could see neutrinos," he says.

"We're looking for a particle—a particle that's almost always involved in very violent reactions, high energy, things like black holes, active galactic nuclei, supernova and gamma ray bursts. It would be very surprising if something like IceCube didn't see astrophysical neutrinos. It would be huge news either way," he adds. "It's a very cutting-edge, frontier experiment. As a scientist, you search for projects like this."

The goal of the AMANDA/IceCube experiments is to detect astrophysical or cosmological neutrinos, as opposed to atmospheric neutrinos, which are locally produced via the interaction of cosmic radiation with the earth's atmosphere.

The telescope has proven itself, Stamatikos explains, because it can detect atmospheric neutrinos at a rate of two to three per day. Scientists are combing the data obtained from AMANDA over the past several years to see if astrophysical neutrinos also are part of the data collected from the telescope.

Neutrinos are unique cosmic messengers since they seldom interact with matter and are not electrically charged and, hence, are unaffected by magnetic fields, says Stamatikos.

"A neutrino will point directly back to its source, making neutrino astronomy possible. Neutrino astronomy literally opens up a new window on the universe since we use a particle, not photons (radiation) to "see" what's out there," he says.

However, seeing a neutrino is difficult—it has very little mass and interacts weakly with matter, says Stamatikos. But they can be detected indirectly due to their interactions with matter.

"The caveat is that neutrinos rarely interact so you need a very large detector volume to increase the probability of detection via their interaction with the matter comprising the detector. AMANDA is a 10-megaton scientific instrument that uses the ice at the geographic South Pole as its detector medium. On occasion, a neutrino will interact with the ice and in the collision a particle known as a muon is created, whose motion through the ice generates a streak of bluish light known as Cherenkov Radiation," he says.

His own research involves looking for a possible connection between gamma ray bursts (GRBs) and high-energy astrophysical neutrinos by comparing AMANDA's observations with GRB position and timing data determined by such satellite detectors as NASA's Compton Gamma Ray Observatory (CGRO).

"Gamma ray bursts have remained an enigma since their discovery in the early 1970s," Stamatikos explains. "They are transient flashes of gamma ray radiation distributed randomly across the sky, located at cosmological distances. The detection of neutrinos from GRBs would help reveal part of the physical mechanisms of the progenitor event(s), thought to be either the merger of compact objects (neutron star/neutron star, neutron star/black hole, etc.,) or the death of massive stars (collapsars)."

Recently, strong evidence has been observed for a GRB-supernova connection. An absence of neutrinos from GRB will help constrain models that predict them and also probe the possibility of GRBs being the sources of the highest energy cosmic rays, he notes.

"I search AMANDA data for neutrino signals occurring at the same time and place as documented GRBs. The expected neutrino signal is determined by computer simulation based upon the application of experimentally measured GRB parameters and theoretical models. This is the groundwork that will be extended to more sensitive instruments such as IceCube and Swift, NASA's next generation GRB satellite detector," he says

Among the unexpected pleasures Stamatikos found at the South Pole was the intense sense of community and trust among people living and working there. He also experienced the isolation inherent in being so far away from home and civilization.

"There's a bit of detachment. You can't take being connected via satellite for granted. You have to really maximize your time. They try their best to make you feel at home.

"I think you'd almost have to go back to the colonial days to get a sense of the isolation and the interconnected nature of everyone," he says. Although everyone at the pole has a very specific job to do, they also pitch in and take turns doing routine chores. "There is a real sense of people helping each other," he says.

Stamatikos also has studied dark matter, another hot topic in astrophysics. As far back as he can remember—even as a young child—he loved science. His parents emigrated to the United States from Rhodes, Greece, in 1970 and he is the first member of the family to attend college.

"Essentially, scientists are like children that never lost their desire or their annoying tenacity to always ask 'why, why, why.' All people go through this in their lives—look at the 2-year-old who constantly asks why. Well, the scientist will never stop asking that.

"As I went through my education, I found out pretty early that the most fundamental field for me that has something to say about virtually everything is physics. Physics is the mother of all sciences. Anything you do can always be traced back to something physical. I've always had a fascination with the universe, the stars, looking up at a dark sky and wondering where is everything going, where did we come from."

Stamatikos says he's quite fortunate to be studying astrophysics at this point in history, which he says, is rife with cutting-edge research at the frontier of discovery.

"It's a golden age in cosmology and astrophysics because now we're really able to test some of these theories and get precision measurements, and throw out some theories or pursue the models that seem to fit the data that we're getting."

Stamatikos plans to return to UB in March to give a lecture about his work on the AMANDA project and research on GRBs. He also will give a public lecture about his experiences in Antarctica.

For more information about AMANDA, visit the University of Wisconsin's website at http://amanda.physics.wisc.edu/.