D. Light Curve During the Newtonian transition
At t
tNR (see Eq. 81) the afterglow reaches the
Newtonian Sedov-Taylor phase. During this phase the adiabatic
hydrodynamic is described by Eq. 83. Frail et al.
[107]
calculate the synchrotron spectrum and light curve of the afterglow in
this stage. The energy scaling implies that
B
t-3/5 and
e,min
t-6/5. Combined together this yields
m
t-3. Using the standard assumptions of equipartition
and of a power law electron's distribution they find :
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(97) |
This late time light curve provides a simple "calorimetric" estimate of the afterglow energy at this stage (see Section IID). Additionally as the radio flux is rather large and as it varies on a scale of several month it can be used for search of orphan radio afterglows (see Levinson et al. [215] and Section VIIK2).