论文标题
来自紧凑型二进制脉冲星的宇宙射线正音调
Cosmic ray positrons from compact binary millisecond pulsars
论文作者
论文摘要
在过去的十年中，新的中子恒星已经出现：紧凑型二进制毫秒脉冲星（CBMSP）。由于这些脉冲星及其同伴恒星处于典型的分离$ 10^{11} $ cm的紧密轨道上，因此它们的风相互作用强烈形成固有的冲击。在冲击时重新计算的电子峰值对可以达到约10个TEV的能量，这使得该新人群成为GEV-TEV宇宙射线正电子的潜在来源。我们提出了一个分析模型，该模型是CBMSPS内部冲击的正电子通量和光谱的分析模型。我们发现，输入冲击的对的最小能量$ e _ {\ min} $对于量化将正上音被注入到星际介质中的能量谱至关重要。我们首次测量CBMSP的银河尺度高度，$ z_e = 0.4 \ pm0.1 $ kpc，在纠正了观察性偏置，以免发现它们接近银河平面。由此，我们估计的局部密度为5-9 kpc $^{ - 3} $，在银河系中估算了2-7,000个CBMSP。然后，我们在各向同性扩散近似中传播对，发现总人口的正电子通量大约是当前已知系统的52倍。对于$ e _ {\ min} $ 1至50 GEV之间的$，我们的模型仅预测CBMSP对在地球上观察到的100 GEV的弥漫性正电子通量的较小贡献。我们还量化了由于有序的银河磁场引起的各向异性转运的影响，这可以大大改变附近来源的弥散通量。最后，我们发现一个接近银河平面的单个“隐藏” CBMSP可以产生与AMS-02测量值600 GEV相当的正电子通量，如果其沿着有序的银河野外线线沿着有序的田间线线，而其合并的电子和正电子通量在更高的能量上可以接近Calet，dampe and CaleT dampe and dampe and dampe and dampe and dampe and dampe and dampe and dampe and dampe and dampe and dampe and dampe and dampe and。
A new population of neutron stars has emerged during the last decade: compact binary millisecond pulsars (CBMSPs). Because these pulsars and their companion stars are in tight orbits with typical separations of $10^{11}$ cm, their winds interact strongly forming an intrabinary shock. Electron-positron pairs reaccelerated at the shock can reach energies of about 10 TeV, which makes this new population a potential source of GeV-TeV cosmic ray positrons. We present an analytical model for the fluxes and spectra of positrons from intrabinary shocks of CBMSPs. We find that the minimum energy $E_{\min}$ of the pairs that enter the shock is critical to quantify the energy spectrum with which positrons are injected into the interstellar medium. We measure for the first time the Galactic scale height of CBMSPs, $z_e=0.4\pm0.1$ kpc, after correcting for an observational bias against finding them close to the Galactic plane. From this, we estimate a local density of 5-9 kpc$^{-3}$ and an extrapolated total of 2-7 thousand CBMSPs in the Galaxy. We then propagate the pairs in the isotropic diffusion approximation and find that the positron flux from the total population is about two times higher than that from the 52 currently known systems. For $E_{\min}$ between 1 and 50 GeV, our model predicts only a minor contribution from CBMSPs to the diffuse positron flux at 100 GeV observed at Earth. We also quantify the effects of anisotropic transport due to the ordered Galactic magnetic field, which can change the diffuse flux from nearby sources drastically. Finally, we find that a single "hidden" CBMSP close to the Galactic plane can yield a positron flux comparable to the AMS-02 measurements at 600 GeV if its line-of-sight to Earth is along the ordered Galactic field lines, while its combined electron and positron flux at higher energies would be close to the measurements of CALET, DAMPE and Fermi-LAT.
