Magnetars in the Metagalaxy: An Origin for Ultra-High-Energy Cosmic Rays in the Nearby Universe
Magnetars in the Metagalaxy: An Origin for Ultra-High-Energy Cosmic Rays in the Nearby Universe
复制标题
DOI：
10.1086/374776
复制
发表时间：
2002-08
期刊：
影响因子：
--
通讯作者：
J. Arons
中科院分区：
文献类型：
--
作者：
J. Arons
我展示了新诞生的磁星（具有petagauss表面磁场的中子星）的相对论性风，其初始自旋速率接近离心分裂极限，发生在所有具有大质量恒星形成的正常星系中，可以提供具有E-1注入光谱的超相对论性光离子的来源，在更高的能量下陡峭到E-2，最高截止在1021-1022 eV。与宇宙微波背景的相互作用在地球上产生的光谱与能量高达1020 eV的几倍的超高能宇宙射线（uhecr）的光谱相比是有利的。对观测结果的拟合表明，约5%-10%的磁星天生具有足够高的旋转速率和电压，可以加速UHECR。在这些中子星的早期自旋下降过程中，入射到地球上的光谱的形式敏感地取决于引力波损失的机制和大小：纯电磁自旋下降（E -1注入谱）在1020 eV以下产生GZK特征[E3J(E)谱的平坦化]，而不是一个截止点，而如果引力波损失足够强，使注入谱在1020 eV以上变得陡峭，则会出现中等的GZK截止点。1020 eV以上的通量来自相对较近星系（D 100 EeV）的磁星，该模型预测引力波应变~3 × 10-21。这种引力辐射的爆发应该与超高能量粒子的爆发有关。俄歇实验应该每隔几年就能看到能量超过100 EeV的粒子爆发。
I show that the relativistic winds of newly born magnetars (neutron stars with petagauss surface magnetic fields) with initial spin rates close to the centrifugal breakup limit, occurring in all normal galaxies with massive star formation, can provide a source of ultrarelativistic light ions with an E-1 injection spectrum, steepening to E-2 at higher energies, with an upper cutoff at 1021-1022 eV. Interactions with the cosmic microwave background yield a spectrum at the Earth that compares favorably with the spectrum of ultra-high-energy cosmic rays (UHECRs) observed at energies up to a few times 1020 eV. The fit to the observations suggests that ~5%-10% of the magnetars are born with rotation rates and voltages sufficiently high to allow the acceleration of the UHECR. The form the spectrum incident on the Earth takes depends sensitively on the mechanism and the magnitude of gravitational wave losses during the early spin-down of these neutron stars: pure electromagnetic spin-down (the E-1 injection spectrum) yields a GZK feature [a flattening of the E3J(E) spectrum] below 1020 eV, rather than a cutoff, while a moderate GZK cutoff appears if gravitational wave losses are strong enough to steepen the injection spectrum above 1020 eV. The flux above 1020 eV comes from magnetars in relatively nearby galaxies (D 100 EeV air showers, the model predicts gravitational wave strains ~3 × 10-21. Such bursts of gravitational radiation should correlate with bursts of ultra-high-energy particles. The Auger experiment should see bursts of particles with energy above 100 EeV every few years.