The Slow Decay of Some Radio Afterglows , a Puzzle for the Simplest GRB Fireball Model

The decay of half of the GRB radio afterglows with long temporal monitoring is significantly slower than at optical frequencies, contrary to what is expected in the simplest fireball model. We investigate four ways to decouple the radio and optical decays: an evolving index of the power-law distribution of the shock-accelerated electrons, the presence of a… (More)