It was recently discovered that in some regions of the Galaxy, the cosmic-ray (CR) abundance is several orders of magnitude higher than previously thought. Additionally, there is evidence that in molecular cloud envelopes, the CR ionization may be dominated by electrons. We show that for regions with high, electron-dominated ionization, the penetration of CR electrons into molecular clouds is modulated by the electric field that develops as a result of the charge they deposit. We evaluate the significance of this novel mechanism of self-modulation and show that the CR penetration can be reduced by a factor of a few to a few hundred in high-ionization environments, such as those found near the Galactic center.

最近发现，在银河系的某些区域，宇宙射线 (CR) 丰度比以前认为的要高几个数量级。此外，有证据表明在分子云包络中，CR 电离可能由电子主导。我们表明，对于电子主导的高电离区域，CR 电子向分子云中的渗透受到由于它们沉积的电荷而产生的电场的调节。我们评估了这种新型自调制机制的重要性，并表明在高电离环境（例如在银河中心附近发现的环境）中，CR 穿透可以减少几到几百倍。