First Light for the Fermi Space Telescope
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August 26, 2008: NASA's newest space telescope, formerly known as GLAST, has passed its orbital checkout with flying colors, kicking off a mission to explore the violent and unpredictable gamma ray universe.
Right: An artist's concept of the newly-minted Fermi Gamma-ray Space Telescope. [more]
"Enrico Fermi was the first person to suggest how cosmic particles could be accelerated to high speeds," said Paul Hertz, chief scientist for NASA's Science Mission Directorate at NASA Headquarters in Washington. "His theory provides the foundation for understanding the new phenomena his namesake telescope will discover."
For two months following the spacecraft's June 11, 2008, launch, scientists tested and calibrated its two instruments, the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM).
Today, the Large Area Telescope team unveiled an all-sky image showing the glowing gas of the Milky Way,, and a flaring galaxy billions of light-years away. The map combines 95 hours of the instrument's "first light" observations:
Above: A portion of Fermi's "first light" map of the gamma-ray heavens. Click to view.
A similar image, produced by NASA's now-defunct Compton Gamma-ray Observatory, took years of observations to produce. With Fermi's superior sensitivity, new discoveries are sure to follow.
Fermi's Large Area Telescope scans the entire sky every three hours when operating in "survey mode," which will occupy most of the telescope's observing time during the first year of operations. These fast snapshots let scientists monitor rapid changes characteristic of the violent gamma-ray universe. The telescope is sensitive to photons with energies ranging from 20 MeV (million electron volts) to over 300 GeV (billion electron volts). The high end of this range, which corresponds to energies more than 5 million times greater than dental X-rays, is little explored.
The spacecraft's secondary instrument, the GBM, spotted 31 explosions known as gamma-ray bursts in its first month of operations alone. These high-energy blasts occur when massive stars die or when orbiting neutron stars spiral together and merge.
The GBM is sensitive to less energetic gamma rays than the Large Area Telescope, giving it a complementary view of the broad gamma-ray spectrum. Working together, the two instruments may finally unravel some of the knottiest mysteries of gamma-ray bursts.
"The past few decades have been a golden age for astronomy," says GBM principal investigator Chip Meegan of the Marshall Space Flight Center. Fermi, he believes, is going to keep the good times rolling. "I'm delighted to be a part of it."
Stay tuned to Science@NASA for more news from Fermi and the gamma-ray universe.
Editor: Dr. Tony Phillips | Credit: Science@NASA
Fermi (GLAST) -- mission home page
A Violent History of Time -- (Science@NASA) An introduction to the Fermi mission and the puzzle of Gamma-ray bursts
Above: A Fermi animation of the Vela pulsar, which beams radiation every 89 milliseconds as it spins. The pulses are shown slowed by 20 times. Credit: NASA/DOE/International LAT Team
NASA's Fermi mission is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S.
NASA's Future: US Space Exploration Policy