New map of the Milky Way charts where stars are bornMarch 24, 2006(Boston) - A team of astronomers from Boston University's Institute for Astrophysical Research has produced the clearest map to-date of the giant gas clouds in the Milky Way that serve as the birthplaces of stars. Using a powerful telescope, the astronomers tracked emissions of a rare form of carbon monoxide called 13CO to chart a portion of our home galaxy and its star-forming molecular clouds. The researchers hope the new illustration will aid in the identification of additional clouds and study of their internal structure to better understand the origin of stars like the sun, which began its life in such a cloud about 5 billion years ago. The data and images are published in the March issue of the Astrophysical Journal Supplement. The eight-year project, called the Boston University-Five College Radio Astronomy Observatory (FCRAO) Galactic Ring Survey (GRS), was led by a team of astronomers based at BU, the University of Cologne in Germany, and the University of Massachusetts.
To produce the detailed image, the astronomers mapped the location of 13CO in the Milky Way using a large radio telescope operated by the FCRAO of the University of Massachusetts that captures and images radio emissions at a frequency near 100,000 MHz - about 1,000 times higher than FM stations. When viewed in the emission from 13CO, the clouds are far more transparent than the more traditionally studied 12CO which allowed the team to peer more deeply into their interior. "The value of such high range imaging is that it enables us to identify the underlying patterns of gas distribution and speeds that point toward the key physical processes occurring within the molecular gas phase of the interstellar medium," said Dr. Mark Heyer, a researcher from UMass involved in the project. Using a new receiver developed at UMass, the astronomers could depict the structure of the clouds faster and with much finer detail than any previous attempts. As an added benefit, the distribution of the clouds also delineates the spiral structure of the Milky Way. "Ironically, because we live inside the Milky Way, we know more about the shapes of far more distant galaxies better than our own," said James Jackson, astronomy professor at BU and lead investigator of the study. "The GRS map helps us better understand the configuration of our home galaxy and its components." "Upon seeing the GRS image, I knew right away it was something terrific. It was like the first time I put on glasses as a kid, and wondered how I ever got along without knowing about every shape, contour and detail of the world around me," said Dr. Ronak Shah, a researcher from BU who worked on the project. "The GRS has that affect on a lot of us. We thought we understood the Milky Way and then the GRS revealed so much more detail to explore." According to Dr. Robert Simon, now at the University of Cologne, but who started the project with Jackson in 1998 at BU, the information from the GRS will constitute an important new database for the study of molecular clouds and Milky Way structure for generations of astronomers. The scientists are now closely analyzing the image and one of the initial findings is the probable identification of dark, cold molecular clouds in the earliest stages of star development. "Data from the Galactic Ring Survey have shown that these clouds are the counterparts to active, bright star-forming clouds, but because they have not yet been heated by the embedded stars, they are much colder and quieter," said Jackson. "Follow-up studies of these clouds will provide additional important clues about the origin of stars since we'll be able to examine them at an earlier point in their life." Another interesting result is that all of the molecular clouds studied so far have similar lumpy structures, regardless of their size, mass, and star-forming activity. These lumps will eventually become stars and, according to the researchers, this similarity suggests that all clouds form stars of various masses in roughly the same proportion. The Milky Way is a vast disk of 100 billion stars, gas, and dust and because it is flat, the map is long and narrow. Since most of the Galaxy lies in the Southern skies, unreachable from Northern Hemisphere telescopes, and because many of the molecular gas clouds are concentrated toward its inner regions, only a portion was imaged. The Institute for Astrophysical Research (IAR) was founded in 1998 in order to promote and facilitate research and education in astrophysics at Boston University. The IAR supports research by BU Astronomy faculty members, graduate and undergraduate students, and postdoctoral and senior research associates. In addition, the IAR manages and coordinates the use of astrophysical research facilities and promotes the design, development, and operation of instruments and telescopes for astronomical research. Founded in 1839, Boston University is an internationally recognized institution of higher education and research. With more than 30,000 students, it is the fourth largest independent university in the United States. BU contains 17 colleges and schools along with a number of multi-disciplinary centers and institutes which are central to the school's research and teaching mission. Boston University | |||||||||||||||||||||
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Related Milky Way News Articles New virtual telescope zooms in on Milky Way's super-massive black hole An international team, led by astronomers at the MIT Haystack Observatory, has obtained the closest views ever of what is believed to be a super-massive black hole at the center of the Milky Way galaxy. Closest Look Ever at the Edge of a Black Hole Astronomers have taken the closest look ever at the giant black hole in the center of the Milky Way. By combining telescopes in Hawaii, Arizona, and California, they detected structure at a tiny angular scale of 37 micro-arcseconds - the equivalent of a baseball seen on the surface of the moon, 240,000 miles distant. UCI scientists discover minimum mass for galaxies By analyzing light from small, faint galaxies that orbit the Milky Way, UC Irvine scientists believe they have discovered the minimum mass for galaxies in the universe - 10 million times the mass of the sun. GLAST Observatory renamed for Fermi, reveals entire gamma-ray sky The U.S. Department of Energy (DOE) and NASA announced today that the Gamma-Ray Large Area Space Telescope (GLAST) has revealed its first all-sky map in gamma rays. Hubble unveils colourful star birth region on 100 000th orbit milestone In commemoration of the NASA/ESA Hubble Space Telescope completing its 100 000th orbit around the Earth in its 18th year of exploration and discovery, scientists have aimed Hubble to take a snapshot of a dazzling region of celestial birth and renewal. Study shows clumps and streams of dark matter in inner regions of the Milky Way Using one of the most powerful supercomputers in the world to simulate the halo of dark matter that envelopes our galaxy, researchers found dense clumps and streams of the mysterious stuff lurking in the inner regions of the halo, in the same neighborhood as our solar system. Caltech astronomers describe the bar scene at the beginning of the universe Bars abound in spiral galaxies today, but this was not always the case. A group of 16 astronomers, led by Kartik Sheth of NASA's Spitzer Science Center at the California Institute of Technology, has found that bars tripled in number over the past seven billion years, indicating that spiral galaxies evolve in shape. Hubble's sweeping view of the Coma Galaxy Cluster The NASA/ESA Hubble Space Telescope captures the magnificent starry population of the Coma Cluster of Galaxies, one of the densest known galaxy collections in the Universe. Team hopes to use new technology to search for ETs A Johns Hopkins astronomer is a member of a team briefing fellow scientists about plans to use new technology to take advantage of recent, promising ideas on where to search for possible extraterrestrial intelligence in our galaxy. CSI: Milky Way team works scene of dead star Like a team of forensic detectives in a television show that could be called "CSI: Milky Way," a University of Chicago astrophysicist and his associates are piecing together how a mysterious infrared ring got left around a dead star that displays a magnetic field trillions of times more intense than Earth's. More Milky Way News Articles |
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