Refreshed Shocks and Late-time Flares
There can be "refreshed" shocks if the central engine continues to release fast-moving matter in small amounts even out to late times, these new shocks will catch up with the external shock to produce something like a late-time internal shock. This explanation has been invoked to explain the frequent flares seen in X-rays and at other wavelengths in many bursts, though some theorists are uncomfortable with the apparent demand that the progenitor (which one would think would be destroyed by the GRB) continues to remain active for very long.
Read more about this topic: Gamma-ray Burst Emission Mechanisms
Famous quotes containing the words refreshed and/or shocks:
“What signify a few lives lost in a century or two? The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. It is its natural manure.”
—Thomas Jefferson (1743–1826)
“Order is Heaven’s first law; and this confessed,
Some are, and must be, greater than the rest,
More rich, more wise; but who infers from hence
That such are happier, shocks all common sense.
Condition, circumstance, is not the thing;
Bliss is the same in subject or in king.”
—Alexander Pope (1688–1744)