Penn State is an institutional partner in a new effort to investigate the structure of our galaxy, the evolution of nearby galaxies and the nature of dark energy. The effort is the newest phase of the Sloan Digital Sky Survey (SDSS-IV), an international collaboration of more than 200 astronomers at more than 40 institutions.
"The SDSS has been one of the most productive endeavors in the history of astronomy, and it provides exciting scientific opportunities to Penn State faculty and students," said Donald Schneider, head of the Department of Astronomy and Astrophysics.
The SDSS-IV survey has three primary scientific programs. The first is to explore the compositions and motions of stars across the entire Milky Way in unprecedented detail. SDSS-IV will use an instrument that is sensitive to infrared light to peer through the dust in our galaxy to investigate the properties of over 100,000 stars in our own galaxy.
"The unique capabilities of the infrared instrument will help us to understand the dynamics and compositions of stellar populations in our galaxy, binary stars, and the properties of planet-hosting stars discovered by the Kepler mission," said Assistant Professor of Astronomy and Astrophysics Suvrath Mahadevan.
In addition to the Sloan Foundation's 2.5-meter telescope in New Mexico, SDSS-IV will obtain observations with the 2.5-meter Irinie du Pont telescope at Las Campanas Observatory, high in the Chilean Andes, where the skies are among the clearest on Earth. The Chilean telescope will allow a full study of the Milky Way, reaching areas of the sky that are inaccessible from New Mexico. It also will be used to investigate of the Magellanic Clouds -- nearby dwarf galaxies that are always below the horizon in New Mexico.
The second program of SDSS-IV also will improve our understanding of the large-scale structure of the universe. The survey will measure the expansion history of the universe through 80 percent of cosmic history, back to times when the universe was less than 3 billion years old. These detailed measurements will improve constraints on the nature of dark energy, the most mysterious experimental result in modern physics.
"These observations of distant objects also will extend greatly our ability to monitor the variations of the emission from quasars, providing insights into how quasar winds, which have speeds of millions of miles per hour, are created," said Niel Brandt, Distinguished Professor of Astronomy and Astrophysics. "These violent motions, ultimately powered by material falling into supermassive black holes, are crucial to our understanding of the growth of black holes and the evolution of their host galaxies."