Gamma-ray Large Area Space Telescope

The Fermi Gamma-ray Space Telescope , formerly referred to as the “Gamma-ray Large Area Space Telescope (GLAST)”, is a space observatory

Space observatory

A space observatory is any instrument in outer space which is used for observation of distant planets, galaxies, and other outer space objects...

being used to perform gamma-ray astronomy

Gamma-ray astronomy

Gamma-ray astronomy is the astronomical study of the cosmos with gamma rays. Gamma-rays are the most energetic form of "light" that travel across the universe, and gamma-rays thus have the smallest wavelength of any wave in the electromagnetic spectrum.Gamma-rays are created by celestial events...

observations from low Earth orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

. Its main instrument is the Large Area Telescope (LAT), with which astronomers mostly intend to perform an all-sky survey studying astrophysical

Astrophysics

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties of celestial objects, as well as their interactions and behavior...

and cosmological

Physical cosmology

Physical cosmology, as a branch of astronomy, is the study of the largest-scale structures and dynamics of the universe and is concerned with fundamental questions about its formation and evolution. For most of human history, it was a branch of metaphysics and religion...

phenomena such as active galactic nuclei, pulsar

Pulsar

A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...

s, other high-energy sources and dark matter

Dark matter

In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

. Another instrument aboard Fermi, the Gamma-ray Burst Monitor (GBM; formerly GLAST Burst Monitor), is being used to study gamma-ray bursts.

Fermi was launched on 11 June 2008 at 16:05 GMT aboard a Delta II

Delta II

Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

7920-H rocket. The mission is a joint venture of NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

, the United States Department of Energy

United States Department of Energy

The United States Department of Energy is a Cabinet-level department of the United States government concerned with the United States' policies regarding energy and safety in handling nuclear material...

, and government agencies in France, Germany, Italy, Japan, and Sweden.

Overview

Fermi includes two scientific instruments, the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The LAT is an imaging gamma-ray detector (a pair-conversion

Pair-conversion

A pair-conversion instrument detects high-energy gamma rays by providing an environment—generally a thin foil of dense metal, commonly tungsten—in which they tend to generate electron-positron pairs, and then using standard particle-physics techniques such as a microstrip detector to detect these...

instrument) which detects photons with energy from about 30 million to about 300 billion electron volts (30 MeV to 300 GeV), with a field of view of about 20% of the sky; it may be thought of as a sequel to the EGRET

Egret

An egret is any of several herons, most of which are white or buff, and several of which develop fine plumes during the breeding season. Many egrets are members of the genera Egretta or Ardea which contain other species named as herons rather than egrets...

instrument on the Compton gamma ray observatory

Compton Gamma Ray Observatory

The Compton Gamma Ray Observatory was a space observatory detecting light from 20 KeV to 30 GeV in Earth orbit from 1991 to 2000. It featured four main telescopes in one spacecraft covering x-rays and gamma-rays, including various specialized sub-instruments and detectors...

. The GBM consists of 14 scintillation detectors (twelve sodium iodide

Sodium iodide

Sodium iodide is a white, crystalline salt with chemical formula NaI used in radiation detection, treatment of iodine deficiency, and as a reactant in the Finkelstein reaction.-Uses:Sodium iodide is commonly used to treat and prevent iodine deficiency....

crystals for the 8 keV to 1 MeV range and two bismuth germanate

Bismuth germanate

Bismuth germanium oxide is an inorganic chemical compound with main use as a scintillator. It forms cubic crystals....

crystals with sensitivity from 150 keV to 30 MeV), and can detect gamma-ray bursts in that energy range across the whole of the sky not occluded by the Earth.

General Dynamics

General Dynamics Corporation is a U.S. defense conglomerate formed by mergers and divestitures, and as of 2008 it is the fifth largest defense contractor in the world. Its headquarters are in West Falls Church , unincorporated Fairfax County, Virginia, in the Falls Church area.The company has...

Advanced Information Systems (formerly Spectrum Astro and now Orbital Sciences) in Gilbert, Arizona

Gilbert, Arizona

-Demographics:As of July 1, 2009, Maricopa Association of Governments, Census 2000. United States Census Bureau. there were 217,521 people, 74,147 housing units, and 3.01 persons per household....

designed and built the spacecraft

Spacecraft

A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

that carries the instruments. It travels in a low, circular orbit with a period of about 95 minutes. Its normal mode of operation maintains its orientation so that the instruments will look away from the earth, with a “rocking” motion to equalize the coverage of the sky. The view of the instruments will sweep out across most of the sky about 16 times per day. The spacecraft can also maintain an orientation that points to a chosen target.

Both science instruments underwent environmental testing, including vibration, vacuum, and high and low temperatures to ensure that they can withstand the stresses of launch and continue to operate in space. They were integrated with the spacecraft at the General Dynamics ASCENT facility in Gilbert, Arizona.

Data from the instruments are available to the public through the Fermi Science Support Center web site. Software for analyzing the data is also available.

GLAST renamed Fermi Gamma-ray Space Telescope

Fermi gained its new name in 2008.

NASA’s Alan Stern

Alan Stern

S. Alan Stern is an American planetary scientist. He is the principal investigator of the New Horizons mission to Pluto....

, associate administrator for Science at NASA Headquarters, launched a public competition 7 Feb 2008, closing 31 Mar 2008, to rename GLAST in a way that would “capture the excitement of GLAST’s mission and call attention to gamma-ray and high-energy astronomy... something memorable to commemorate this spectacular new astronomy mission... a name that is catchy, easy to say and will help make the satellite and its mission a topic of dinner table and classroom discussion”.

On 26 Aug 2008, GLAST was renamed the “Fermi Gamma-ray Space Telescope” in honor of Enrico Fermi

Enrico Fermi

Enrico Fermi was an Italian-born, naturalized American physicist particularly known for his work on the development of the first nuclear reactor, Chicago Pile-1, and for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics...

, a pioneer in high-energy physics.

Mission

NASA designed the mission with a five-year lifetime, with a goal of ten years of operations.

The key scientific objectives of the Fermi mission have been described as:

To understand the mechanisms of particle acceleration in active galactic nuclei
Active galactic nucleus
An active galactic nucleus is a compact region at the centre of a galaxy that has a much higher than normal luminosity over at least some portion, and possibly all, of the electromagnetic spectrum. Such excess emission has been observed in the radio, infrared, optical, ultra-violet, X-ray and...

(AGN), pulsars, and supernova remnants (SNR).
Resolve the gamma-ray sky: unidentified sources and diffuse emission.
Determine the high-energy behavior of gamma-ray bursts and transients.
Probe dark matter
Dark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

(e.g. by looking for an excess of gamma rays from the center of the Milky Way) and early Universe.
Search for evaporating primordial micro black holes (MBH) from their presumed gamma burst signatures [Hawking Radiation component].

The National Academies of Sciences ranked this mission as a top priority. Many new possibilities and discoveries are anticipated to emerge from this single mission and greatly expand our view of the Universe

Universe

The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...

. (The following list is abbreviated as discoveries are made. To read about discoveries already made, see "Discoveries" below.)

Blazars and active galaxies

Study energy spectra and variability of wavelengths of light coming from blazars so as to determine the composition of the black hole jets aimed directly at Earth -- whether they are

(a) a combination of electron

Electron

The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...

s and positron

Positron

The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...

s or

(b) only proton

Proton

The proton is a subatomic particle with the symbol or and a positive electric charge of 1 elementary charge. One or more protons are present in the nucleus of each atom, along with neutrons. The number of protons in each atom is its atomic number....

Gamma-ray bursts

Study gamma-ray bursts with an energy range several times more intense than ever before so that scientists may be able to understand them better.

Neutron star
Neutron star
A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...

s

Study younger, more energetic pulsar

Pulsar

s in the Milky Way

Milky Way

The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...

than ever before so as to broaden our understanding of star

Star

A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

s. Study the pulsed emissions of magnetosphere

Magnetosphere

A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...

s so as to possibly solve how they are produced. Study how pulsars generate winds of interstellar particles.

Milky Way galaxy

Provide new data to help improve upon existing theoretical models of our own galaxy.

Gamma-ray background radiation

Study better than ever before whether ordinary galaxies

Galaxy

A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...

are responsible for gamma-ray background radiation. The potential for a tremendous discovery awaits if ordinary sources are determined to be irresponsible, in which case the cause may be anything from self-annihilating dark matter to entirely new chain reactions among interstellar particles that have yet to be conceived.

The early universe

Study better than ever before how concentrations of visible and ultraviolet light change over time. The mission should easily detect regions of spacetime where gamma-rays interacted with visible or UV light to make matter. This can be seen as an example of E=mc² working in reverse, where energy is converted into mass, in the early universe.

Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

Study better than ever before how our own Sun

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

produces gamma rays in solar flare

Solar flare

A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy . The flare ejects clouds of electrons, ions, and atoms through the corona into space. These clouds typically reach Earth a day...

Dark matter
Dark matter
In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

Search for evidence that dark matter is made up of weakly interacting massive particles, complementing similar experiments already planned for the Large Hadron Collider

Large Hadron Collider

The Large Hadron Collider is the world's largest and highest-energy particle accelerator. It is expected to address some of the most fundamental questions of physics, advancing the understanding of the deepest laws of nature....

as well as other underground detectors. The potential for a tremendous discovery in this area is possible over the next several years.

Fundamental physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

Test better than ever before certain established theories of physics

Physics

Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

, such as whether the speed of light in vacuum

Vacuum

In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...

remains constant regardless of wavelength

Wavelength

In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

. Einstein

Albert Einstein

Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...

's general theory of relativity contends that it does, yet some models in quantum mechanics

Quantum mechanics

Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...

and quantum gravity

Quantum gravity

Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...

predict that it may not. Search for gamma rays emanating from former black holes that once exploded, providing yet another potential step toward the unification of quantum mechanics and general relativity. Determine whether photon

Photon

In physics, a photon is an elementary particle, the quantum of the electromagnetic interaction and the basic unit of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force...

s naturally split into smaller photons, as predicted by quantum mechanics and already achieved under controlled, man-made experimental conditions.

Unknown discoveries

Scientists estimate a very high possibility for new scientific discoveries, even revolutionary discoveries, emerging from this single mission.

Prelaunch

On 4 Mar 2008 the spacecraft arrived at the Astrotech payload processing facility in Titusville, Florida

Titusville, Florida

Titusville is a city in Brevard County, Florida in the United States. It is the county seat of Brevard County. Nicknamed Space City, USA, Titusville is on the Indian River, west of Merritt Island and the Kennedy Space Center and south-southwest of the Canaveral National Seashore...

. On 4 Jun 2008, after several previous delays, launch status was retargeted for June 11 at the earliest, the last delays resulting from the need to replace the Flight Termination System batteries. The launch window extended from 11:45 a.m. until 1:40 p.m. EDT (15:45-17:40 GMT) daily, until 7 Aug 2008.

Launch

Launch occurred successfully on 11 Jun 2008 at 16:05, and the spacecraft separated from the carrier rocket about 75 minutes later. The spacecraft departed from pad B at Cape Canaveral Air Force Station Space Launch Complex 17 aboard a Delta 7920H-10C

Delta II

Delta II was an American space launch system, originally designed and built by McDonnell Douglas. Delta II is part of the Delta rocket family and was in service from 1989 until November 1, 2011...

rocket.

Orbit

Fermi resides in a low-earth circular orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

at an altitude of 550 km (341.8 mi), and at an inclination of 28.5 degrees.

Software modifications

GLAST received some minor modifications to its computer software 2008-06-23.

LAT/GBM computers operational

Computers operating both the LAT and GBM and most of the LAT’s components were turned on, 2008-06-24. The LAT high voltage was turned on, 2008-06-25, and it began detecting high-energy particles from space, but minor adjustments were still needed to calibrate the instrument. The GBM high voltage was also turned on, 2008-06-25, but the GBM still required one more week of testing/calibrations before searching for gamma-ray bursts.

Sky survey mode

After presenting an overview of the Fermi instrumentation and goals, Jennifer Carson of SLAC National Accelerator Laboratory

SLAC National Accelerator Laboratory

The SLAC National Accelerator Laboratory, originally named Stanford Linear Accelerator Center, is a United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S...

had concluded that the primary goals were “all achievable with the all-sky scanning mode of observing”. Fermi switched to "sky survey mode" on 26 June 2008 so as to begin sweeping its field of view over the entire sky every three hours (every two orbits).

Discoveries

Pulsar discovery

The first major discovery came when the space telescope detected a pulsar

Pulsar

in the CTA 1 supernova

Supernova

A supernova is a stellar explosion that is more energetic than a nova. It is pronounced with the plural supernovae or supernovas. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months...

remnant that appeared to emit radiation in the gamma ray

Gamma ray

Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...

bands only, a first for its kind. This new pulsar sweeps the earth every 316.86 milliseconds and is about 4,600 light years away.

Greatest GRB energy release

In September 2008, the gamma-ray burst GRB 080916C

GRB 080916C

GRB 080916C is a gamma-ray burst that was recorded on September 16, 2008 in the Carina constellation and detected by NASA's Fermi Gamma-ray Space Telescope. It was the most powerful gamma-ray burst ever recorded...

in the constellation Carina

Carina (constellation)

Carina is a constellation in the southern sky. Its name is Latin for the keel of a ship, and it was formerly part of the larger constellation of Argo Navis until that constellation was divided in three.-Stars:...

was recorded by the Fermi telescope. This burst is notable as having “the largest apparent energy release yet measured”. The explosion had the power of about 9,000 ordinary supernovae, and the relativistic

Theory of relativity

The theory of relativity, or simply relativity, encompasses two theories of Albert Einstein: special relativity and general relativity. However, the word relativity is sometimes used in reference to Galilean invariance....

jet of material ejected in the blast must have moved at a minimum of 99.9999% the speed of light

Speed of light

The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...

. Overall, GRB 080916C had “the greatest total energy, the fastest motions, and the highest-energy initial emissions” ever seen.

Cosmic rays and supernova remnants

In February 2010, it was announced that Fermi-LAT had determined that supernova remnant

Supernova remnant

A supernova remnant is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way.There are two...

s act as enormous accelerators for cosmic particles

Cosmic ray

Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...

. This determination fulfills one of the stated missions for this project.

Background gamma ray sources

In March 2010 it was announced that active galactic nuclei

Active galactic nucleus

An active galactic nucleus is a compact region at the centre of a galaxy that has a much higher than normal luminosity over at least some portion, and possibly all, of the electromagnetic spectrum. Such excess emission has been observed in the radio, infrared, optical, ultra-violet, X-ray and...

are not responsible for most gamma-ray background radiation. Though active galactic nuclei do produce some of the gamma-ray radiation detected here on Earth, less than 30% originates from these sources. The search now is to locate the sources for the remaining 70% or so of all gamma-rays detected. Possibilities include star forming galaxies

Star formation

Star formation is the process by which dense parts of molecular clouds collapse into a ball of plasma to form a star. As a branch of astronomy star formation includes the study of the interstellar medium and giant molecular clouds as precursors to the star formation process and the study of young...

, galactic mergers, and yet-to-be explained dark matter

Dark matter

In astronomy and cosmology, dark matter is matter that neither emits nor scatters light or other electromagnetic radiation, and so cannot be directly detected via optical or radio astronomy...

interactions

Self-interacting dark matter

In astrophysics self-interacting dark matter is a hypothetical form of dark matter consisting of particles with strong self-interactions. This type of dark matter was postulated to resolve a number of conflicts between observations and simulations on the galactic scale and smaller....

Fermi bubbles

In November 2010, it was announced two gamma-ray & x-ray bubbles were detected around Earth’s galaxy, the Milky Way. The bubbles extend about 25 thousand light years

Light Years

Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....

distant above and below the center of the galaxy. The galaxy's diffuse gamma-ray fog hampered prior observations, but the discovery team led by D. Finkbeiner, building on research by G. Dobler, worked around this problem.

Gamma-ray Burst Monitor (GBM)

The Gamma-ray Burst Monitor (GBM) (formerly GLAST Burst Monitor) detects sudden flares of gamma-rays produced by gamma ray burst

Gamma ray burst

Gamma-ray bursts are flashes of gamma rays associated with extremely energetic explosions that have been observed in distant galaxies. They are the most luminous electromagnetic events known to occur in the universe. Bursts can last from ten milliseconds to several minutes, although a typical...

s and solar flare

Solar flare

s. Its scintillator

Scintillator

A scintillator is a special material, which exhibits scintillation—the property of luminescence when excited by ionizing radiation. Luminescent materials, when struck by an incoming particle, absorb its energy and scintillate, i.e., reemit the absorbed energy in the form of light...

s are on the sides of the spacecraft to view all of the sky which is not blocked by the earth. The design is optimized for good resolution in time and photon energy.

"Gamma-ray bursts are so bright we can see them from billions of light years away, which means they occurred billions of years ago, and we see them as they looked then," stated Charles Meegan of NASA's Marshall Space Flight Center

Marshall Space Flight Center

The George C. Marshall Space Flight Center is the U.S. government's civilian rocketry and spacecraft propulsion research center. The largest center of NASA, MSFC's first mission was developing the Saturn launch vehicles for the Apollo moon program...

.

The Gamma-ray Burst Monitor has detected gamma rays from positron

Positron

The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...

s generated in powerful thunderstorms.

US team institution

NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's Marshall Space Flight Center
Marshall Space Flight Center
The George C. Marshall Space Flight Center is the U.S. government's civilian rocketry and spacecraft propulsion research center. The largest center of NASA, MSFC's first mission was developing the Saturn launch vehicles for the Apollo moon program...

, University of Alabama in Huntsville
University of Alabama in Huntsville
The University of Alabama in Huntsville is a state-supported, public, coeducational research university, located in Huntsville, Alabama, United States, is accredited by the Southern Association of Colleges and Schools to award baccalaureate, master's and doctoral degrees, and is organized in five...

German team institutions

Max Planck Institut für Extraterrestrische Physik
Max Planck Institute for Extraterrestrial Physics
The Max Planck Institute for Extraterrestrial Physics is a Max Planck Institute, located in Garching, near Munich, Germany.In 1991 the Max Planck Institute for Physics and Astrophysics split up into the Max Planck Institute for Extraterrestrial Physics, the Max Planck Institute for Physics and the...

Large Area Telescope (LAT)

The Large Area Telescope (LAT) detects individual gamma rays using technology similar to that used in terrestrial particle accelerator

Particle accelerator

A particle accelerator is a device that uses electromagnetic fields to propel charged particles to high speeds and to contain them in well-defined beams. An ordinary CRT television set is a simple form of accelerator. There are two basic types: electrostatic and oscillating field accelerators.In...

s. Photons hit thin metal sheets, converting to electron

Electron

-positron

Positron

The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...

pairs, via a process known as pair production

Pair production

Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon . For example an electron and its antiparticle, the positron, may be created...

. These charged particles pass through interleaved layers of silicon microstrip detector

Microstrip detector

A microstrip detector is a particle detector designed to consist of a large number of identical components laid out along one axis of a two-dimensional structure, generally by lithography...

s, causing ionization

Ionization

Ionization is the process of converting an atom or molecule into an ion by adding or removing charged particles such as electrons or other ions. This is often confused with dissociation. A substance may dissociate without necessarily producing ions. As an example, the molecules of table sugar...

which produce detectable tiny pulses of electric charge. Researchers can combine information from several layers of this tracker to determine the path of the particles. After passing through the tracker, the particles enter the calorimeter

Calorimeter

A calorimeter is a device used for calorimetry, the science of measuring the heat of chemical reactions or physical changes as well as heat capacity. Differential scanning calorimeters, isothermal microcalorimeters, titration calorimeters and accelerated rate calorimeters are among the most common...

, which consists of a stack of caesium iodide

Caesium iodide

Caesium iodide is an ionic compound often used as the input phosphor of an x-ray image intensifier tube found in fluoroscopy equipment....

scintillator

Scintillator

crystals to measure the total energy of the particles. The LAT's field of view is large, about 20% of the sky. The resolution of its images is modest by astronomical standards, a few arc minutes for the highest-energy photons and about 3 degrees at 100 MeV

MEV

MeV and meV are multiples and submultiples of the electron volt unit referring to 1,000,000 eV and 0.001 eV, respectively.Mev or MEV may refer to:In entertainment:* Musica Elettronica Viva, an Italian musical group...

. The LAT is a bigger and better successor to the EGRET instrument on NASA

NASA

's Compton Gamma Ray Observatory

Compton Gamma Ray Observatory

satellite in the 1990s. Several countries produced the components of the LAT, who then sent the components for assembly at SLAC National Accelerator Laboratory

SLAC National Accelerator Laboratory

US team institutions

Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...

, Physics Department, Fermi group & Hansen Experimental Physics Laboratory
Hansen Experimental Physics Laboratory
The Hansen Experimental Physics Laboratory was founded in 1947 and is a facility at the Stanford University aiming to promote interdisciplinary enterprises across different branches of science....
SLAC National Accelerator Laboratory
SLAC National Accelerator Laboratory
The SLAC National Accelerator Laboratory, originally named Stanford Linear Accelerator Center, is a United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S...

, Particle Astrophysics group and Kavli Institute for Particle Astrophysics and Cosmology
NASA Goddard Space Flight Center, Astrophysics Science Division
NASA Ames Research Center
U.S. Naval Research Laboratory, High Energy Space Environment (HESE) branch
Ohio State University
Ohio State University
The Ohio State University, commonly referred to as Ohio State, is a public research university located in Columbus, Ohio. It was originally founded in 1870 as a land-grant university and is currently the third largest university campus in the United States...

, Physics Department
University of California, Santa Cruz
University of California, Santa Cruz
The University of California, Santa Cruz, also known as UC Santa Cruz or UCSC, is a public, collegiate university; one of ten campuses in the University of California...

, Physics Department and Institute for Particle Physics
Santa Cruz Institute for Particle Physics
Santa Cruz Institute of Particle Physics is the largest sub department within the Physics department at the University of California, Santa Cruz. This department has several world class faculty...
Sonoma State University
Sonoma State University
Sonoma State University is a public, coeducational business and liberal arts college affiliated with the California State University system. The main campus is located in Rohnert Park, California, United States and lies approximately south of Santa Rosa and north of San Francisco...

, Department of Physics & Astronomy
University of Washington
University of Washington
University of Washington is a public research university, founded in 1861 in Seattle, Washington, United States. The UW is the largest university in the Northwest and the oldest public university on the West Coast. The university has three campuses, with its largest campus in the University...
Purdue University Calumet
Purdue University Calumet
Purdue University Calumet is a school within the Purdue University system that is located in Hammond, Indiana in the Northwest Indiana portion of the Chicago metropolitan area.-Schools:Purdue University Calumet is academically organized into six schools:...
University of Denver
University of Denver
The University of Denver is currently ranked 82nd among all public and private "National Universities" by U.S. News & World Report in the 2012 rankings....

German team institutions

Max Planck Institute for Extraterrestrial Physics
Max Planck Institute for Extraterrestrial Physics
The Max Planck Institute for Extraterrestrial Physics is a Max Planck Institute, located in Garching, near Munich, Germany.In 1991 the Max Planck Institute for Physics and Astrophysics split up into the Max Planck Institute for Extraterrestrial Physics, the Max Planck Institute for Physics and the...
Max Planck Institute for Physics
Max Planck Institute for Physics
Max Planck Institute for Physics is a physics institute in Munich, Germany that specializes in High Energy Physics and Astroparticle physics. It is part of the Max-Planck-Gesellschaft and is also known as the Werner Heisenberg Institute, after its first director.It was founded as the Kaiser Wilhelm...

Japanese team institutions

University of Tokyo
University of Tokyo
, abbreviated as , is a major research university located in Tokyo, Japan. The University has 10 faculties with a total of around 30,000 students, 2,100 of whom are foreign. Its five campuses are in Hongō, Komaba, Kashiwa, Shirokane and Nakano. It is considered to be the most prestigious university...
Tokyo Institute of Technology
Tokyo Institute of Technology
The Tokyo Institute of Technology is a public research university located in Greater Tokyo Area, Japan. Tokyo Tech is the largest institution for higher education in Japan dedicated to science and technology. Tokyo Tech enrolled 4,850 undergaraduates and 5006 graduate students for 2009-2010...
Japan Aerospace Exploration Agency
Japan Aerospace Exploration Agency
The , or JAXA, is Japan's national aerospace agency. Through the merger of three previously independent organizations, JAXA was formed on October 1, 2003, as an Independent Administrative Institution administered by the Ministry of Education, Culture, Sports, Science and Technology and the...
Hiroshima University
Hiroshima University
, located in the Japanese cities of Higashihiroshima and Hiroshima, was established 1949 by the merger of a number of national educational institutions.-History:Under the National School Establishment Law, Hiroshima University was established on May 31, 1949...
Ibaraki University
Ibaraki University
, Japan, is a national university located in Ibaraki Prefecture, with campuses in the cities of Mito, Ami and Hitachi. It was established on May 31, 1949, integrating these prewar institutions: Mito High School , Ibaraki Normal School , Ibaraki Juvenile Normal School , and Taga Technical...

Italian team institutions

Italian Space Agency
Italian Space Agency
The Italian Space Agency is a government agency established in 1988 to fund, regulate and coordinate space exploration activities in Italy...

Science Data Center
INAF
INAF
The Istituto Nazionale di Astrofisica , or INAF for short, is the most important Italian institution conducting scientific research in astronomy and astrophysics. Researches performed by the scientific staff of the Institute go from the study of the planets and minor bodies of the solar system up...

Istituto di Radioastronomia di Bologna
Istituto di Radioastronomia di Bologna
The Istituto di Radioastronomia di Bologna is one of the Italian institutes that had already been part of the Consiglio Nazionale delle Ricerche , now part of the Istituto Nazionale di Astrofisica .Many learned researchers in astronomy, physics, engineering or...
INAF
INAF
The Istituto Nazionale di Astrofisica , or INAF for short, is the most important Italian institution conducting scientific research in astronomy and astrophysics. Researches performed by the scientific staff of the Institute go from the study of the planets and minor bodies of the solar system up...

Istituto di Fisica Cosmica, Milano
INFN and University of Bari
University of Bari
The University of Bari is a university located in Bari, Italy. It was founded in 1925 and is organized in 12 Faculties.-Organization:These are the 13 faculties in which the university is divided into:* Faculty of Agricultural Science...
INFN and University of Padova
INFN and University of Perugia
University of Perugia
University of Perugia is a public-owned university based in Perugia, Italy. It was founded in 1308, as attested by the Bull issued by Pope Clement V certifying the birth of the Studium Generale....
INFN and University of Pisa
University of Pisa
The University of Pisa , located in Pisa, Tuscany, is one of the oldest universities in Italy. It was formally founded on September 3, 1343 by an edict of Pope Clement VI, although there had been lectures on law in Pisa since the 11th century...
INFN and University of Rome Tor Vergata
University of Rome Tor Vergata
The University of Rome Tor Vergata is a public university located in Rome, Italy. It is one of the largest research-based institutions in the country. The University is an international center for research and education and it is well known for scientific studies...
INFN and University of Trieste
University of Trieste
The University of Trieste is a medium-sized university in Trieste in the Friuli-Venezia Giulia region of Italy. The university consists of 12 faculties, boasts a wide and almost complete range of university courses and currently has about 23,000 students enrolled and 1,000 professors...
INFN and University of Udine
University of Udine
The University of Udine is a university in the city of Udine . It was founded in 1978 as part of the reconstruction plan of Friuli after the earthquake in 1976...

French team institutions

Institut de Recherche en Astrophysique et Planétologie, Université Paul Sabatier
Paul Sabatier University
Paul Sabatier University is a French university, in the Academy of Toulouse.Founded in 1229, the University of Toulouse is one of the oldest in Europe. Today’s Toulouse III was named for Paul Sabatier, winner of the 1912 Nobel prize in chemistry, when it was established on the foundations of the...

, Toulouse
Laboratoire AIM, CEA Saclay
Laboratoire Leprince-Ringuet de l'École Polytechnique
École Polytechnique
The École Polytechnique is a state-run institution of higher education and research in Palaiseau, Essonne, France, near Paris. Polytechnique is renowned for its four year undergraduate/graduate Master's program...
University of Bordeaux I
University of Bordeaux
University of Bordeaux is an association of higher education institutions in and around Bordeaux, France. Its current incarnation was established 21 March 2007. The group is the largest system of higher education schools in southwestern France. It is part of the Academy of Bordeaux.There are seven...
Laboratoire Univers et Particules, Montpellier 2 University
Montpellier 2 University
Montpellier 2 University is a French university in the académie of Montpellier. It is one of the three universities formed in 1970 from the original University of Montpellier...

Education and public outreach

Education and public outreach are important components of the Fermi project. The main Fermi education and public outreach website at http://glast.sonoma.edu offers gateways to resources for students, educators, scientists, and the public. NASA’s Education and Public Outreach

NASA Education and Public Outreach Group

NASA’s Education and Public Outreach group at Sonoma State University, founded in 1999, is a provider of educational materials for students, educators, scientists, and the public. Funded by NASA, employees work together to create educational guides, fact sheets, worksheets, posters, games, and...

(E/PO) group operates the Fermi education and outreach resources at Sonoma State University

Sonoma State University

Sonoma State University is a public, coeducational business and liberal arts college affiliated with the California State University system. The main campus is located in Rohnert Park, California, United States and lies approximately south of Santa Rosa and north of San Francisco...

Rossi Prize

The 2011 Bruno Rossi Prize

Bruno Rossi Prize

The Bruno Rossi Prize is awarded annually by the High Energy Astrophysics division of the American Astronomical Society "for a significant contribution to High Energy Astrophysics, with particular emphasis on recent, original work". Named after astrophysicist Bruno Rossi, the prize is awarded with...

was awarded to Bill Atwood, Peter Michelson and the Fermi LAT team "for enabling, through the development of the Large Area Telescope, new insights into neutron stars, supernova remnants, cosmic rays, binary systems, active galactic nuclei and gamma-ray bursts."

External links

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