论文标题
GRB 170817a作为刷新的冲击余波观看了离轴
GRB 170817A as a Refreshed Shock Afterglow viewed off-axis
论文作者
论文摘要
向外部冲击系统注入能量，从而产生余辉到伽马射线爆发（GRB）可能会导致发射的重新塑造。在这里，我们调查了重新启动的刷新冲击余星的外轴观点。我们发现，当从射流开头的外部看时，余辉曲线的特征是缓慢上升或长斑点，最大通量由总系统能量确定。使用与引力波检测到的二进制中子星合并GW170817相关的GRB170817A的宽带余辉数据，我们表明具有简单顶级射流的刷新冲击模型可以重现观察到的余辉特征。我们考虑了两个特殊的刷新冲击模型：一次能量注射；以及一段连续的能量注入时期。最佳拟合模型参数给我们的第一或第二个模型的$θ_j= 5.2^{+1.1} _ { - 0.6}〜$或$ 〜6.3^{+1.7} _ { - 1.1} $ b = 16.0^{+3.4} _ { - 1.1}〜$或$ 〜17.8^{+4.5} _ { - 2.9} $ deg，一个初始的摩托质等效能量$ e_1 = （0.3^{+3.5} _ { - 0.3}〜$或$ 〜0.5^{+6.7} _ { - 0.2}）\ times10^{52} $ erg和总/最终/final/final/final/final/final/final/final/final/final/final/final/final refreshed shock enger $ e _ {\ rm总计} =（0.42^{+5.6} _ { - 0.4}〜$或$ 〜1.26^{+18.2} _ { - 0.7}）\ times10^{53} $ erg。第一个拟合的模型更喜欢初始批量的lorentz因子$γ_{0,1} <60 $，中央值相对较低，为$γ_{0,1} = 19.5 $，这表明在这种情况下，轴上喷气机本来可以是``失败grb''。另外，我们的第二个模型与轴上观察者的明亮GRB一致，其中$γ_{0,1} = 162.2^{+219.7} _ { - 122.1} $。由于$θ_j\ simm/3 $的低洛伦兹因子或喷气开口角，这两种型号都无法重现GRB170817A中观察到的$γ$ ray排放，因此需要诸如Cocoon Shock-Break-Break-Breakout之类的其他解释。
Energy injection into the external shock system that generates the afterglow to a gamma-ray burst (GRB) can result in a re-brightening of the emission. Here we investigate the off-axis view of a re-brightened refreshed shock afterglow. We find that the afterglow light-curve, when viewed from outside of the jet opening angle, could be characterised by a slow rise, or long-plateau, with a maximum flux determined by the total system energy. Using the broadband afterglow data for GRB170817A, associated with the gravitational wave detected binary neutron star merger GW170817, we show that a refreshed shock model with a simple top-hat jet can reproduce the observed afterglow features. We consider two particular refreshed shock models: a single episode of energy injection; and a period of continuous energy injection. The best fit model parameters give a jet opening angle, for our first or second model of $θ_j=5.2^{+1.1}_{-0.6}~$or$~6.3^{+1.7}_{-1.1}$ deg, an inclination to the line of sight $ι=16.0^{+3.4}_{-1.1}~$or$~17.8^{+4.5}_{-2.9}$ deg, an initial isotropic equivalent kinetic energy $E_1 = (0.3^{+3.5}_{-0.3}~$or$~0.5^{+6.7}_{-0.2})\times10^{52}$erg and a total/final, refreshed shock energy $E_{\rm total}=(0.42^{+5.6}_{-0.4}~$or$~1.26^{+18.2}_{-0.7})\times10^{53}$erg. The first model fitting prefers an initial bulk Lorentz factor $Γ_{0,1}<60$, with a comparatively low central value of $Γ_{0,1}=19.5$, indicating that, in this case, the on-axis jet could have been a `failed-GRB'. Alternatively, our second model is consistent with a bright GRB for an on-axis observer, with $Γ_{0,1}=162.2^{+219.7}_{-122.1}$. Due to the low-Lorentz factor or the jet opening angles at $θ_j\simι/3$, both models are unable to reproduce the $γ$-ray emission observed in GRB170817A, which would therefore require an alternative explanation such as cocoon shock-breakout.
