AI 中文总结
该研究推导了超新星激波通过星周介质突破产生高能中微子的光变曲线与能谱，发现其或可显著贡献河外高能中微子背景，且不会过度产生高能伽马射线背景。
AI 中文摘要
核心坍缩超新星（SN）前身星在爆炸前不久出现的质量损失增强现象似乎较为普遍，会在约10^14-10^15 cm处形成致密、光学厚的星周介质（CSM）。我们推导了非相对论性超新星激波通过此类CSM突破时所发射高能中微子的光变曲线与能谱的解析描述，该描述依赖于激波速度和CSM参数，同时考虑了流体动力学结构及电磁（EM）能谱的演化，此时激波从辐射介导态转变为无碰撞态。这种演化决定了时变中微子产生效率、质子/中子最大能量以及对产生光深。通常，中微子能量的很大一部分会在爆炸后数天内、突破阶段及EM光变曲线峰值前发射，其中1-100 TeV的中微子携带约10%激波加速质子的能量。对于致密CSM构型，对产生效应会抑制高能光子（>1 GeV）的逃逸。若质量损失增强现象普遍存在，且假设激波加速质子携带约10%无碰撞激波能量，则CSM超新星突破可能对观测到的高能中微子背景有显著贡献，且不会过度产生相应的高能伽马射线背景。预计在1（10）km²探测器中，每年会产生>1个（>10个）中微子事件的超新星发生率约为0.05（1）次/年。
英文摘要
Enhanced mass loss from core-collapse supernova (SN) progenitors shortly before explosion appears to be common, creating a compact, optically thick circumstellar medium (CSM) at $\sim10^{14}-10^{15}$ cm. We derive an analytic description of the light curves and spectra of high-energy neutrinos emitted by nonrelativistic SN shock breakouts through such CSM, as a function of shock velocity and CSM parameters, accounting for the evolution of the hydrodynamic structure and the electromagnetic (EM) spectrum as the shock transitions from being radiation-mediated to collisionless. This evolution determines the time-dependent neutrino production efficiency, the maximum proton/neutrino energy, and the pair-production optical depth. A significant fraction of the neutrino energy is typically emitted within a few days of explosion, during breakout and before the EM light curve peak, with $1-100$ TeV neutrinos carrying $\approx10\%$ of the energy of shock-accelerated protons. The escape of high-energy photons ($>1$~GeV) is suppressed by pair-production for compact CSM configurations. If enhanced mass losses are common, and assuming that shock-accelerated protons carry $\approx10\%$ of the collisionless shock energy, CSM SN breakouts may significantly contribute to the observed high-energy neutrino background, without overproducing a corresponding high-energy gamma-ray background. SNe producing $>1$ neutrino events in a $1\left(10\right){\rm km^2}$ detector are expected at a rate of $\sim0.05\left(1\right){\rm yr^{-1}}$.
CommentsSubmitted to ApJ, comments welcome
