Compton Observatory Science Highlights: Gamma-ray
Bursts
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The discovery that gamma-ray bursts come uniformly
from all directions in the sky indicates that the bursts are not confined
to our Milky Way galaxy, but are probably due to huge explosions in the
distant reaches of the universe.
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The careful measurements of gamma-ray burst brightness
has revealed that there are surprisingly few dim bursts being measured.
Assuming that dimmer bursts come from further away implies that burst distribution
has an outer edge.
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The detection of high-energy gamma rays hours after the
bursts indicates some kind of lingering energetic activity must be occurring
in the sources after the initial event.
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Compton Observatory Science Highlights: Diffuse
Emission
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The mapping of the Milky Way galaxy using the 26Al isotope
uncovered surprising localized enhancements in emission. This has important
consequences for how chemical elements are created in our galaxy.
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The Discovery of an extended region of electron-positron
annihilation emision in the Galactic center region - the so called "Galactic
Annihilation Fountain."
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The discovery of gamma-ray line emission from the supernova
remnant Cas A. This is also very important for the synthesis of elements.
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Compton Observatory Science Highlights: Compact
Galactic Sources
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An increase in the number of detected gamma-ray pulsars
from 2 to 7 - this has resulted in much greater understanding of the basic
physics of these rapidly rotating neutron stars.
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The discovery of the "Bursting Pulsar", an exotic object
near the galactic center which is unlike any previously known gamma-ray
emitter.
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A large increase in the number of mysterious, unidentified
gamma-ray sources both in and out of the plane of the Milky Way galaxy.
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The discovery, with the help of x-ray observations, that
the previously unidentified source known as Geminga is a gamma-ray pulsar.
This could be an important clue to the nature of several other unidentified
sources.
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Compton Observatory Science Highlights: Extragalactic
Sources
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The emergence of blazar Active Galactic Nuclei (AGN) -
highly variable cores of distant galaxies - as a primary source of cosmic
gamma rays at the highest energies.
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Sensitive measurements of the energy distribution for
another type of active galaxy known as Seyfert galaxies, which show that
the production of gamma-ray photons dies out at much lower energies than
previously thought.
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The detection of diffuse gamma-ray emission from the Large
Magellanic Cloud, a nearby galaxy whose gamma-ray flux indicates that cosmic
rays are galactic in origin - helping to solve a longstanding problem in
high-energy astrophysics.
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