by Kitta MacPherson

Scientists at Princeton have formalized a collaboration with researchers at the Ludwig-Maximilians-University Munich that will employ supercomputers to aid them in arriving at a better understanding of galaxy formation.

The work will be centered at the Princeton Institute for Computational Science and Engineering (PICSciE) and the University Observatory Munich.

Understanding how galaxies are formed and what conditions are necessary to produce them is one of the biggest questions in astronomy, according to Jeremiah Ostriker, a professor in the Department of Astrophysical Sciences and director of PICSciE. The partnership is designed to improve on the present-day quandary that computations designed to simulate the formation of galaxies over time have not produced results that look realistic.

“Until now, people have not succeeded in their computer simulations of taking calculations and making galaxies that look like real galaxies,” said Ostriker, the collaboration’s leader at Princeton. “We want to take the prevailing cosmology and compute it in enough detail to see if we get the building blocks of what we observe.”

Central to the research partnership will be the upgrade of Artemis, a supercomputer at PICSciE, that will double its capacity and computing speed. Enhancements of the energy-efficient SGI device are under way.

Superfast computers that can crunch a vast array of numbers are essential tools to scientists looking to answer many questions in modern cosmology, according to Andreas Burkert, the chair for astronomy and astrophysics for theoretical and numerical astrophysics at the Munich university. “The universe is so complex, with everything happening at the same time, so it helps to use simulations to guide you,” added Burkert, who will lead the Munich side of the collaboration.

Computer simulations of galactic evolution attempt to represent the interaction of billions of particles, some visible and some invisible, with operating instructions built upon current understanding of what has happened to create structures in the universe over time.

Using the new, more powerful supercomputer, the researchers plan to revise the basic formulas used in simulations to make them more realistic and see if we ultimately produce something that more closely matches the visible universe. “We want to know whether we can explain the origin of our Milky Way and whether we can predict what will happen in the future,” Burkert said.

Burkert described Ostriker as “one of the heroes of the field” of cosmology, explaining why the group came together. “Jerry’s been there from the beginning,” Burkert said. “He established the field. For us, it’s a pleasure he wants to work with us.”

Other key researchers in the partnership include David Spergel, the Charles A. Young Professor of Astronomy on the Class of 1897 Foundation and chair of the Department of Astrophysical Sciences at Princeton, and Thorsten Naab, a professor of physics at the University Observatory Munich.

The groups have been collaborating for some time but decided to formalize the arrangement earlier this year. PICSciE is housed in Princeton’s new Lewis Library and has offices for staff, faculty and postdoctoral fellows and space for computers and visualization equipment.

Other Research highlights

In results from the largest health policy study of its kind, a Mexican health care program created in 2003 has been found effective in reducing crippling health care costs among poorer households. The results reflect the success of the Seguro Popular program, and arise from an evaluation conducted by U.S. researchers, including a Prince-ton faculty member, in collaboration with researchers in Mexico. “We were able to scientifically establish that the program achieved its main goal to reduce health care costs,” said Kosuke Imai, an assistant professor of politics at Princeton who developed a new statistical method for the study.

To read about this and other research findings, visit www.princeton.edu/main/news/science/.