发表机构
Indian Institute of Science Education and Research Thiruvananthapuram; University of Leeds（印度科学教育研究所特里万德琅分校; 利兹大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过二维RHD模拟研究黑洞自旋对坍缩星喷流突破的影响，发现自旋阈值a>0.001时喷流成功突破，且突破时间与喷流光度呈幂律关系。
AI 中文摘要
长伽马射线暴（LGRBs）被认为起源于大质量沃尔夫-拉叶（WR）星的核心坍缩，导致形成自旋黑洞，进而驱动相对论性喷流。一旦喷流从恒星包层中穿出，便产生瞬时辐射。我们使用PLUTO代码进行了二维轴对称相对论流体动力学（RHD）模拟，以模拟由克尔黑洞驱动的、基于吸积的半自洽喷流。对于两个前身星模型，我们分别采用对应于10 M⊙和25 M⊙的WR星的黑洞质量4 M⊙和5 M⊙。与以往研究不同，我们的模拟采用连续喷流注入，注入功率通过由GRMHD模拟启发的经验关系与黑洞自旋和吸积相关联，从而能够在10^48-10^52 erg s^-1范围内对喷流能量进行受控探索。我们研究了10 M⊙和25 M⊙的WR前身星的喷流突破，并确定了一个临界自旋阈值：当a ≤ 0.001时喷流受阻，当a > 0.001时喷流成功突破。突破时间（t_B）与喷流光度（L_jet）和自旋（a）显示出相关性，揭示了三个区域：牛顿区域（a ≲ 0.03）、相对论区域（a ≳ 0.3）和中间区域。在突破时喷流头部速度存在二分性，高自旋时β_h ≳ 0.8，较低自旋时β_h ~ 0.35-0.8。在牛顿区域，模拟得到t_B ∝ L_jet^-0.48，比解析预测更陡，且突破时间系统性更长，表明喷流头部标度关系有所修正。在相对论区域，校准后的解析模型显示出更好的一致性，模拟表明喷流传播高效。
英文摘要
Long gamma-ray bursts (LGRBs) are believed to originate from the core collapse of massive Wolf-Rayet (WR) stars, leading to the formation of a spinning black hole that powers a relativistic jet. The prompt emission is produced once the jet emerges from the stellar envelope. We perform 2D axisymmetric RHD simulations using the PLUTO code to model semi-self-consistent, accretion-powered jets launched by Kerr black holes. For the two progenitor models, we adopt black hole masses of $4 M_{\odot}$ and $5 M_{\odot}$ corresponding to WR stars of $10 M_{\odot}$ and $25 M_{\odot}$, respectively. Unlike previous studies, our simulations employ continuous jet injection, with the injected power linked to black hole spin and accretion through an empirical relation motivated by GRMHD simulations, enabling a controlled exploration of jet energetics over $10^{48}$-$10^{52}\,\mathrm{erg\,s^{-1}}$. We investigate jet breakout for WR progenitors of $10\,M_{\odot}$ and $25\,M_{\odot}$ and identify a critical spin threshold: jets are choked for $a \leq 0.001$ and successfully break out for $a > 0.001$. The breakout time ($t_B$) shows a correlation with jet luminosity ($L_{\rm jet}$) and spin ($a$), revealing three regimes: Newtonian ($a \lesssim 0.03$), relativistic ($a \gtrsim 0.3$), and intermediate. A dichotomy is observed in jet head velocity at breakout, with $β_h \gtrsim 0.8$ for high-spin and $β_h \sim 0.35$-$0.8$ for lower spins. In the Newtonian regime, simulations yield $t_B \propto L_{\rm jet}^{-0.48}$, steeper than analytical predictions, with systematically longer breakout times indicating modified jet-head scaling. In the relativistic regime, calibrated analytical models show improved agreement, with simulations indicating efficient jet propagation.
Comments20 pages, 11 figures, Submitted. Comments and suggestions are welcome
