The Milky Way galaxy formed from the merging together of small galaxies early in the history of the universe, according to a picture being built by Rensselaer researchers. Some merging continues today, as small galaxies that pass too close to us are ripped apart, scattering stars throughout the galaxy. Many of the stars that were originally born in the smaller, ancient galaxies still persist to this day, now as stars of the Milky Way.
Building this complex narrative is taking a multidisciplinary team of astronomers and computer scientists, the resources of Rensselaer’s new supercomputing center, computer clusters on campus, and a community computer network called MilkyWay@home, which uses idle time on volunteers’ personal computers.
Astronomer Heidi Newberg, an associate professor of physics, originally began mapping the outer reaches of the Milky Way with funding from NSF. Co-investigator Malik Magdon-Ismail, associate professor of computer science, wrote an algorithm to help her get answers.
The computing became so intensive, however, that far more power was needed. Carlos Varela, associate professor of computer science, and Boleslaw Szymanski, director of the Center for Pervasive Computing and Networking at Rensselaer, brought the necessary expertise in parallel processing and grid computing to the group. A new grant was received from the NSF to support the astroinformatics collaboration.
“We are using computation to try to discern which stars in our galaxy were incorporated into the Milky Way early in the history of the universe,” said Szymanski, “and which are the remnants of those nearby galaxies that were more recently ripped apart.” The project analyzes a huge data set collected by the Sloan Digital Sky Survey. The problem is that the distance of most stars cannot be measured directly. “We create models and compute probabilities that agree with the observations,” he said.
Mapping the History of Our Galaxy (Inside Rensselaer)