早期宇宙中星系周围由流式宇宙射线诱发的电阻加热
Resistive Heating Induced by Streaming Cosmic Rays Around a Galaxy in the Early Universe
AI总结：
研究早期宇宙高红移星系周围流式宇宙射线的电阻加热，发现其在近星系区域主导加热，并削弱所产生磁场，且可经由21厘米信号检验。
摘要：
预计在红移 $z\sim10-20$ 时，宇宙射线（CRs）会从高红移星系中逃逸，因为宇宙射线由第一代恒星的超新星遗迹加速。尽管紫外和X射线光子被广泛认为是星系际介质加热的主要来源，但宇宙射线也可对此作出贡献。当宇宙射线在星系际介质中传播时，除了由宇宙射线电离导致的加热过程外，还会因流式宇宙射线诱发的电子回流而产生电阻加热。我们评估了星系周围的加热率，并将其表示为距星系距离的函数。我们发现，在星系附近 $r\lesssim10^2\\,\mathrm{kpc}$ 范围内，由宇宙射线诱发的电阻加热主导其他加热过程，直到温度达到 $T\sim10^4\\,\mathrm{K}$。我们还重新计算了在X射线加热存在的情况下由流式宇宙射线产生的磁场强度，并表明当计入X射线加热时，所达到的磁场强度可小约1个数量级。“第一代”宇宙射线的存在，未来可通过射电观测中21厘米线图上所印记的宇宙射线加热特征信号得到确认。
英文摘要：
It is expected that cosmic rays (CRs) escape from high-redshift galaxies at redshift $z\sim 10 \, - \, 20$ because CRs are accelerated by supernova remnants of the first stars. Although ultraviolet and X-ray photons are widely considered the main source of heating of the intergalactic medium, CRs can also contribute to it. When the CRs propagate in the intergalactic medium, in addition to the heating process due to CR ionization, resistive heating occurs due to the electron return current induced by the streaming CRs. We evaluate the heating rate around a galaxy as a function of the distance from the galaxy. We find that the resistive heating induced by CRs dominates over the other heating processes in the vicinity of the galaxy $r \lesssim 10^2 \, \mathrm{kpc}$ until the temperature reaches $T\sim 10^4 \, \mathrm{K}$. We also recalculate the strength of the magnetic field generated by streaming CRs under the presence of X-ray heating and show that achieved strength can be about $1$ order of magnitude smaller when the X-ray heating is included. The presence of the "first" CRs could be confirmed from the characteristic signature of CR heating imprinted on the $21$-$\mathrm{cm}$ line map in future radio observations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
