Panaitescu 2006 GRB990123光学和伽玛射线辐射的统一模型

主要内容:
prompt阶段的光学辐射是同步，伽玛是逆康普顿。

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文章信息:

astro-ph/0612504 [abs, ps, pdf, other] :

Title: A unified picture for the gamma-ray and prompt optical emissions of GRB 990123
Authors: A. Panaitescu, P. Kumar
Comments: 9 pages, accepted for publication by MNRAS

The prompt optical emission of GRB 990123 was uncorrelated to the gamma-ray light-curve and exhibited temporal properties similar to those of the steeply-decaying, early X-ray emission observed by Swift at the end of many bursts. These facts suggest that the optical counterpart of GRB 990123 was the large-angle emission released during (the second pulse of) the burst. If the optical and gamma-ray emissions of GRB 990123 have, indeed, the same origin then their properties require that (i) the optical counterpart was synchrotron emission and the gamma-rays arose from inverse-Compton scatterings ("synchrotron self-Compton model"), (ii) the peak-energy of the optical-synchrotron component was at ~20 eV, and (iii) the burst emission was produced by a relativistic outflow moving at Lorentz factor > 450 and at a radius > 10^{15} cm, which is comparable to the outflow deceleration radius. Because the spectrum of GRB 990123 was optically thin above 2 keV, the magnetic field behind the shock must have decayed on a length-scale of <1%>