论文标题
伽马射线爆发的扩展培养基中的喷射繁殖
Jet Propagation in Expanding Medium for Gamma-Ray Bursts
论文作者
论文摘要
二进制中子星（BNS）合并事件GW170817清楚地表明，BNS合并推出了短的伽马射线爆发（SGRB）喷气机。与Collapsar不同，在环境介质是静态的折叠板不同，在BNS中，Jet合并通过合并弹出式繁殖，该合并以很大的速度向外扩展（$ \ sim 0.2c $）。在这里，我们提出了半分析和分析模型，以通过其周围媒体解决GRB喷气机的传播。这些模型通过自以为是的茧来包括茧的射流准则，从而改善了我们以前的模型。我们还对BNS合并和Collapsar中的JET传播进行了一系列2D数值模拟，以测试我们的模型。我们的模型与各个方面的数值模拟一致（射流头半径，茧的侧宽度，射流开口角，包括准直，茧压力，茧压力和喷射cocoon形态）。发现茧的能量组成是不同的，具体取决于环境介质是否正在扩展。在BNS合并喷气机的情况下，Cocoon能量由动能主导，而茧的能量则由折叠术中的内部能量主导。我们的模型对于将电磁对应物估算为引力波很有用。
The binary neutron star (BNS) merger event GW170817 clearly shows that a BNS merger launches a short Gamma-Ray Burst (sGRB) jet. Unlike collapsars, where the ambient medium is static, in BNS mergers the jet propagates through the merger ejecta that is expanding outward at substantial velocities ($\sim 0.2c$). Here, we present semi-analytic and analytic models to solve the propagation of GRB jets through their surrounding media. These models improve our previous model by including the jet collimation by the cocoon self-consistently. We also perform a series of 2D numerical simulations of jet propagation in BNS mergers and in collapsars to test our models. Our models are consistent with numerical simulations in every aspect (the jet head radius, the cocoon's lateral width, the jet opening angle including collimation, the cocoon pressure, and the jet-cocoon morphology). The energy composition of the cocoon is found to be different depending on whether the ambient medium is expanding or not; in the case of BNS merger jets, the cocoon energy is dominated by kinetic energy, while it is dominated by internal energy in collapsars. Our model will be useful for estimating electromagnetic counterparts to gravitational waves.
