The brightest persistent source in the gamma-ray
sky is the Vela pulsar, which is about 1,000 light-years away.
Recorded as GRB 140419A by NASA's Gamma-ray
Coordinates Network, the burst was spotted at 11 p.
bursts are the most luminous explosions in the cosmos, thought to be triggered when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole.
bursts are nearly impossible to study from Earth because our atmosphere blocks the view.
Thousands of gamma-ray
``bursters,'' as such events are called, have been detected since the 1960s, but they remain mysterious, because each one disappears in seconds or minutes and has not been known to recur for further study.
For the first time a connection between dramatic outbursts of high energy gamma-ray
emission and their counterparts at many radio frequencies has been established for a large sample of galaxies.
Data from NASA's Fermi Gamma-ray
Space Telescope indicate that most of the gamma rays emitted by a pulsar arise from far above the pulsar's surface.
It may even be possible to find other gravitational lenses with data from the Fermi Gamma-ray
NASA's Fermi Gamma-ray
Space Telescope is an international and multi-agency astrophysics and particle physics partnership managed by NASA's Goddard Space Flight Center in Greenbelt, Md.
New findings cast doubt on gamma-ray
bursts as producers of these enigmatic particles, which carry energy exceeding 10 billion billion electron volts.
Astronomers were drawn to the distant explosion by a gamma-ray
burst--radiation of extremely high energy.
Symposium on High Energy Gamma-Ray
Astronomy (2d: 2004: Heidelberg, Germany) Ed.
where q is the amount of charge created by the photocathode per detected gamma-ray
, I is the average photocurrent per detector and [f.
observations have suggested that there is an enormous black hole at the center of the galaxy and that as matter is drawn into the hole, it is so intensely heated that antimatter positrons are formed.
GLAST is a next generation high-energy gamma-ray
observatory designed for making observations of celestial gamma-ray
sources in the energy band extending from 10 MeV to more than 100 GeV.