2Mass Project Maps Known Universe

University of Massachusetts astronomers are leading an ambitious $40 million project to map the entire sky using a pair of specially-built infrared telescopes that represent the latest in astronomical imaging technology. The project is a collaboration between UMass and several major research organizations, including the Infrared Processing and Analysis Center at the California Institute of Technology’s Jet Propulsion Lab (JPL/Caltech), and the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. Scientists from 10 organizations will be part of the three-to-five-year project. Nicknamed “2Mass,” the Two Micron All Sky Survey is the first time in almost 30 years scientists have tried to map individual stars and galaxies in the entire “near-infrared” sky. The last such all-sky survey was carried out by Caltech in 1969. The 2Mass project will canvas all of the earth’s northern and southern sky looking for stars and galaxies up to 80,000 times fainter than the preceding survey. Why use infrared technology? Many astronomical objects radiate most of their energy at infrared wavelengths, and certain events such as the birth of stars and condensation of planetary systems can be seen to best advantage through infrared observations. Near-infrared emission is at wavelengths roughly 2-4 times longer than visible light, and permits astronomers to “see through” the obscuring effects of interstellar particles. When the first images from 2Mass began coming in on April 17, astronomers had a lot to celebrate. “First light”as they call it, captured crystal-clear pictures of ring nebulae and other dramatic stellar clusters. “The exciting thing about the first light observations was that the system was performing up to its specifications on the first try,” says UMass astronomer Michael Skrutskie, principal investigator for the 2Mass project. “Things went so well that we were able to begin regular survey observations in mid-May.” The observations took place at the Smithsonian Astrophysical Laboratory’s Whipple Observatory, situated near the top of 8,550-foot Mt. Hopkins, south of Tucson (pictured). Observations will be conducted in the southern hemisphere using a duplicate telescope in place at Cerro Tololo, Chile. Advanced infrared technology is very weather-dependent. The El Nino developing over the Eastern Pacific may wreak havoc with the 2Mass schedule. It is uncertain how much of an impact it will have this year. The 2Mass telescope is a member of a new family of space surveillance instruments based on NICMOS, a state-of-the-art infrared telescope recently installed on the Hubble Space Telescope. Each telescope, according to Skrutskie, will be equipped with a camera that will house three near-infrared arrays, so that the sky can be surveyed simultaneously at three wavelengths. As the survey downloads a continuous stream of data, astronomers will be presented with an embarrassment of riches — cataloging so many new objects in the sky will mean that many hours will go into finding new ways to organize and present enormous amounts of data. The five-year survey is expected to collect an estimated 20 terabytes or more of data. To put that into perspective, one terabyte is roughly equiva-lent to 2,000 multi-volume encyclopedias. Skrutskie estimates that about 15 gigabytes of data will stream nightly from each telescope’s location.It will be processed at the Infrared Processing Center at Caltech/JPL. The result will be catalogs of more than 300 million stars and several million galaxies, as well as an atlas of images covering the entire sky. Currently, 2Mass belongs exclusively to the astronomers. As the daunting supply of data accumulates, Skrutskie envisions increased involvement by mathematicians and computer scientists. New computer programs will be required to make the data accessible. To prepare for this involvement, 2Mass is also part of the “National Partnership for Advanced Computing Infrastructure” (NPACI), led by the University of California, San Diego. Among the other institutions participating in 2Mass are the US Navy, the National Science Foundation, the Universities of Arizona, Florida, Michigan, and the Phillips Lab at Hanscom Field in Bedford, MA. UMass is responsible for the overall project management, developing the infrared cameras, telescopes, and the on-site computing. Editor’s Note: UMass participants in the 2Mass Project also include professors Rae Stiening, Project Director, Stephen Schneider and Martin Weinberg.