The Universe is home to numerous exotic and beautiful phenomena, some of which can generate almost inconceivable amounts of energy. Supermassive black holes, merging neutron stars, streams of hot gas moving close to the speed of light ... these are but a few of the marvels that generate gamma-ray radiation, the most energetic form of radiation, billions of times more energetic than the type of light visible to our eyes. What is happening to produce this much energy? What happens to the surrounding environment near these phenomena? How will studying these energetic objects add to our understanding of the very nature of the Universe and how it behaves?
The Fermi Gamma-ray Space Telescope, formerly GLAST, is opening this high-energy world to exploration and helping us answer these questions. With Fermi, astronomers at long last have a superior tool to study how black holes, notorious for pulling matter in, can accelerate jets of gas outward at fantastic speeds. Physicists are able to study subatomic particles at energies far greater than those seen in ground-based particle accelerators. And cosmologists are gaining valuable information about the birth and early evolution of the Universe.
For this unique endeavor, one that brings together the astrophysics and particle physics communities, NASA has teamed up with the U.S. Department of Energy and institutions in France, Germany, Japan, Italy and Sweden. General Dynamics was chosen to build the spacecraft. Fermi was launched June 11, 2008 at 12:05 pm EDT.
Due to the position in the Earth's orbit, solar illumination has caused a few of the GBM NaI detectors to reach their operational temperature limits. To reduce the temperatures and preserve the detector lifetimes, these detectors have been powered off. The thermal situation will naturally improve within approximately a week as the solar illumination changes with the orbit. When that occurs all of the NaI detectors will be turned on again. Until then, some data will be unavailable. Triggering continues to be enabled but with reduced efficiency due to fewer operating detectors.
Scientists using data from NASA's Fermi Gamma-ray Space Telescope have measured all the starlight produced over 90 percent of the universe's history. The analysis, which examines the gamma-ray output of distant galaxies, estimates the formation rate of stars and provides a reference for future missions that will explore the still-murky early days of stellar evolution.
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The FSSC is pleased to announce the availability of updated Pass 8 data for the LAT. These data files (P8R3) have a residual background that is significantly lower than the previous Pass 8 data (P8R2) and introduce a new event class, which is defined by a set of additional cuts on top of the SOURCE selection. See arXiv:1810.11394 for more details about the P8R3 data and LAT Data Products for more information. New IRFs and isotropic templates for use with the P8R3 data have been released with Fermitools 1.0.0.