Zhou Muni, Zhdankin Vladimir, Kunz Matthew W, Loureiro Nuno F, Uzdensky Dmitri A
Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139.
Center for Computational Astrophysics, Flatiron Institute, New York, NY 10010.
Proc Natl Acad Sci U S A. 2022 May 10;119(19):e2119831119. doi: 10.1073/pnas.2119831119. Epub 2022 May 5.
SignificanceAstronomical observations indicate that dynamically important magnetic fields are ubiquitous in the Universe, while their origin remains a profound mystery. This work provides a paradigm for understanding the origin of cosmic magnetism by taking into account the effects of the microphysics of collisionless plasmas on macroscopic astrophysical processes. We demonstrate that the first magnetic fields can be spontaneously generated in the Universe by generic motions of astrophysical turbulence through kinetic plasma physics, and cosmic plasmas are thereby ubiquitously magnetized. Our theoretical and numerical results set the stage for determining how these "seed" magnetic fields are further amplified by the turbulent dynamo (another central and long-standing question) and thus advance a fully self-consistent explanation of cosmic magnetogenesis.
意义
天文观测表明，具有动力学重要性的磁场在宇宙中无处不在，但其起源仍是一个深奥的谜团。这项工作通过考虑无碰撞等离子体微观物理学对宏观天体物理过程的影响，提供了一个理解宇宙磁性起源的范例。我们证明，宇宙中的第一批磁场可以通过天体物理湍流的一般运动，经由动力学等离子体物理学自发产生，从而使宇宙等离子体普遍被磁化。我们的理论和数值结果为确定这些“种子”磁场如何通过湍流发电机进一步放大（另一个核心且长期存在的问题）奠定了基础，从而推进了对宇宙磁产生的完全自洽解释。
