== Theory Framework of GRB Blasts ==


The theoretical basis of the GRB blast wave can be simply described (first para section 2 Nava+12 http://arxiv.org/pdf/1211.2806.pdf) by these phases (Somehow Nava starts the numbering sequence after acceleration, but I wanted to add it, so I put in a phase 0):

===0. Acceleration Phase===

===I. Coasting  Phase (at Gamma_0)===

Flux_bol ~  t^2   (Ackerman+13 http://arxiv.org/pdf/1303.2908v1.pdf)  ...  or t^(2-s), s the density profile index,  in Nava+12.

===II. Relativistic Deceleration===

There can be adiabatic and radiative sub-phases. 

(The famous Blandford & McKee (1976) is the self–similar solution during the relativistic deceleration phase of adiabatic blast waves.)

This is where most emission takes place; it 

===III. Non-Relativistic Deceleration===

(The famous Sedov–Taylor solution (Sedov 1946; Taylor 1950; von Neumann 1947)  holds in non-rel regime.)

== Mapping Theory Framework on Observations ==



===Afterglow Observations===

====X, Opt, flares and re-brightening====

This is here because although complicated, it relates to BLF measurement and the borderline between prompt and afterglow.

An important paper here is Liang et al.2012 http://adsabs.harvard.edu/cgi-bin/bib_query?arXiv:1210.5142 is a big study of optical afterglows (AGs) presenting distributions and correlations of this optical afterglow peak time method. 

'''X-ray (XRT) AGs are often flare-dominated at early times'''; they are not peaks plus smooth decays - very complicated --- they show lots of flares, etc. in the transition from prompt to AG and even at very late times. 

'''Optical re-brightening''' is common and energetically significant; this is 1e4 s (not to be confused with the SN signal in ~ 2 weeks).  

Optical AGs shows flares, usually not as dramatic as XRT, but then they have very large, major re-brightenings.   Liang+12 found of 146 optical well-measured GRB,  38 optical onset bumps and 47 re-brighting bumps.  The re-brightening bumps are probably a structured jet viewed on-axis.  The KE of the re-brightening bumps are similar to the onset bumps, but the  BLFs are  much lower.  So, re-brightening is a jet phenomenon, and therefore important and GRB-like.