A $1.3 million National Science Foundation grant awarded to Heidi Newberg, associate professor of physics, creates a ground-breaking partnership between U.S. scientists and the new Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) in China.

“This grant is important because it is the first time a U.S. team has partnered with a Chinese-led astronomy project,” said Newberg, who is leading a team of about a dozen U.S. researchers in the partnership.

The partnership gives U.S. astronomers — who are members of Participants in LAMOST or US (PLUS) — access to LAMOST data that will be collected in a forthcoming sky survey. The U.S. team will use the data to plot the position, speed and composition — or “spectrum” — of more than 7 million stars.

Their work will lead to more accurate three-dimensional models of the Milky Way, which could be used to shed new light on the distribution of dark matter in galaxies, how stars and galaxies are formed, and how galactic disks are created, Newberg said.

With a 4-meter wide mirror and 4,000 optical fibers — each controlled by separate motors — the LAMOST is able to collect more spectra simultaneously than any other telescope, Newberg said. Over the course of five years, the LAMOST survey will take the spectra of 7.5 million stars. By comparison, during her work on the Sloan Digital Sky Survey, Newberg initiated a survey of 450,000 stellar spectra over four years.

The spectrum of each star — the light and shadow that it emits — tells cosmologists which direction the star is moving and its chemical composition. By painstakingly plotting the stars within the Milky Way, Newberg and other scientists can produce an accurate three-dimensional model of how stars circulate throughout a galaxy.

“Only now, with the availability of large aperture telescopes with thousands of fibers, is it becoming possible to view a large enough part of our own galaxy in sufficient detail to piece together its global structure and merger history star by star,” Newberg said. “The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), which is a national key project of China, is the most promising facility for obtaining, in the near term, the millions of spectra of galactic stars that we need for this project.”

Newberg’s primary interest is in a diffuse cloud of stars that surrounds the flat disk of the Milky Way.

Her past research has shown that small dwarf galaxies are being broken up by the turbulent gravitational tides circulating within the Milky Way. The stars of these dwarf galaxies are swirled through and around the Milky Way.

The diffuse cloud of stars around the Milky Way’s disk is thought to have been built up from stars born in smaller galaxies that later merged to create the Milky Way.

 “We find stars in these small galaxies that fell into the Milky Way — whether they are intact or not — and know they were not born in our galaxy,” Newberg said. “We’re trying to figure out which stars used to be in the same small galaxy because then we can group them by their family of origin.”

LAMOST, in Xinglong, in China’s industrialized north, is currently undergoing engineering commissioning, and scientists expect their work will begin later this year. The four-year NSF grant includes funding for U.S. astronomers to travel to China, and partial funding for Chinese visiting scholars.

Contact: Mary L. Martialay
Phone: (518) 276-2146
E-mail: martim12@rpi.edu