Overview of radio afterglows observations (invited)

Author: Poonam Chandra

Abstract: Radio observations of Gamma Ray Burst (GRB) afterglows are excellent means to probe the GRB environments and constrain their density nature. Late time radio observations of the GRB afterglow, when it has made transition to non-relativistic phase, can provide most accurate energy estimate independent of the geometry effects. Radio emission also allows us to see important transitions in the afterglow physics, such as synchrotron peak frequency, the cooling break, the trans-relativistic expansion etc., which in turn provide key diagnostics to the fundamental parameters of the explosion. Here I will present a statistical analysis of radio afterglows of GRBs and derive important conclusions and predictions about their properties and detectability. Our sample consists of 304 radio afterglows with around 3000 measurements spread between day one to several hundred days. The prompt emission in radio bands provides a unique opportunity to study GRB interior.