Microphysics and dynamics of the Gamma-Ray Burst 121024A

摘要: Aims. The aim of the study is to constrain physics gamma-ray bursts (GRBs) by analysing multi-wavelength afterglow data set GRB 121024A that covers full range from radio X-rays. Methods. Using multi-epoch broad-band observations afterglow, we measured three characteristic break frequencies synchrotron spectrum. We used six epochs combined XRT and GROND temporal slopes, dust extinction, X-ray absorption, spectral slope with high accuracy. Two more XRT, GROND, APEX, CARMA, EVLA were constraints on therefore micro-physical dynamical parameters. Results. light curves show a simultaneous achromatic at around 49 ks. As result, crossing cooling no suitable explanation for in curve. multi wavelength allow us test two plausible scenarios explaining break: jet break, end energy injection. jet-break scenario requires hard electron spectrum, very low frequency, non-spreading jet. injection avoids these problems, but $\epsilon_e > 1 (k = 2)$, spherical outflow, $\epsilon_B < 10^{-9}$. Conclusions. In extreme microphysical parameters required energy-injection model, favour where $\nu_m \nu_{sa}$ explain observations. This gives physically meaningful parameters, it also naturally explains reported detection linear circular polarisation.