PDA

View Full Version : Fermi Glimpses Wildest-Ever Gamma-Ray Blast



Fraser
2009-Feb-19, 07:50 PM
GRB 080916C's X-ray afterglow appears orange and yellow in this view that merges images from Swift's UltraViolet/Optical and X-ray telescopes. Credit: NASA/Swift/Stefan Immler*Researchers using the Fermi Gamma-ray Space Telescope are reporting a gamma-ray explosion*that*blows away anything they've seen before. The blast, recorded last fall in the constellation Carina, released the energy of 9,000 supernovae.The collapse [...]

More... (http://www.universetoday.com/2009/02/19/fermi-glimpses-wildest-ever-gamma-ray-blast/)

trinitree88
2009-Feb-19, 08:12 PM
GRB 080916C's X-ray afterglow appears orange and yellow in this view that merges images from Swift's UltraViolet/Optical and X-ray telescopes. Credit: NASA/Swift/Stefan Immler*Researchers using the Fermi Gamma-ray Space Telescope are reporting a gamma-ray explosion*that*blows away anything they've seen before. The blast, recorded last fall in the constellation Carina, released the energy of 9,000 supernovae.The collapse [...]

More... (http://www.universetoday.com/2009/02/19/fermi-glimpses-wildest-ever-gamma-ray-blast/)

Fraser. I think the author, Anne, has overlooked the collimation of supernovae gamma ray bursts, which according to Middleditch, runs to ~ a factor of 10,000...so that would put the energy not in inverse square law territory, and at ~ the energy delivered in a normal supernova. Most of a type 2 (high 80's) is in several short prompt neutrino bursts. Less than 10% shows up as kinetic energy of the ejecta and neutron star. A few percent max for the optical display/gamma ray burst.
see:http://adsabs.harvard.edu/abs/2008AAS...212.1305M

slang
2009-Feb-19, 11:03 PM
See also here (http://www.bautforum.com/astronomy/84414-most-powerfeul-grb-ever-detected.html)

GOURDHEAD
2009-Feb-20, 08:27 PM
When estimating the total energy emitted by the gamma ray burster, how to they account for spectrum redshifting? How energetic were the gammas when they were first emitted?