冠状横向磁动力波在一个太阳突出位置
T J Okamoto1, S Tsuneta, T E Berger
1National Astronomical Observatory (NAOJ), Mitaka, Tokyo 181-8588, Japan. joten.okamoto@nao.ac.jp
概括
太阳的突出部分是凉爽的等离子体云. 观测表明振荡结构是阿尔夫文波,可能会加热太阳冠状.
科学领域:
- 血物理学的等离子体物理学
- 太阳天体物理学 太阳天体物理学
- 磁动力学是一种磁动力学.
背景情况:
- 太阳突出点是更冷的等离子云 (10^4 K),悬浮在更热的太阳冠冕 (10^6 K) 中.
- 支持这些突出并加热冠状的机制在很大程度上仍未确定.
- 在突出位置内观察到微型结构.
研究的目的:
- 为了研究在太阳突出处观察到的微型结构的性质.
- 确定这些结构在冠状热中的潜在作用.
- 探索突出振荡与冠状磁场之间的联系.
主要方法:
- 来自Hinode卫星的高分辨率观测的分析.
- 专注于在天空平面上振荡的线状结构.
- 在磁场线上波传播的背景下对振荡的解释.
主要成果:
- 观测到的微型线状结构表现出几分钟周期的振荡.
- 这些振荡与阿尔夫恩波的传播是一致的.
- 阿尔夫恩波沿着冠状磁场线传播.
结论:
- 观察到的振荡可能代表阿尔夫恩波.
- 这些阿尔弗文波可能有助于太阳冠冕的升温.
- 需要进一步的研究来证实阿尔夫恩波在冠状热机制中的作用.
相关概念视频
Momentum And Radiation Pressure
An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because electromagnetic waves contain and transport momentum. The force accounts for the wave's radiation pressure exerted on the object. Maxwell's prediction was confirmed in 1903 by Nichols and Hull by precisely measuring radiation pressures with a torsion balance. The measuring instrument had mirrors suspended from a fiber kept inside a glass container. Nichols...
Magnetostatic Boundary Conditions
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
Magnetic Field Lines
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
Divergence and Curl of Magnetic Field
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
Magnetic Field of a Solenoid
A solenoid is a conducting wire coated with an insulating material, wound tightly in the form of a helical coil. The magnetic field due to a solenoid is the vector sum of the magnetic fields due to its individual turns. Therefore, for an ideal solenoid, the magnetic field within the solenoid is directly proportional to the number of turns per unit length and the current. Conversely, the magnetic field outside the solenoid is zero.
Consider a solenoid with 100 turns wrapped around a cylinder of...
Consider a solenoid with 100 turns wrapped around a cylinder of...
Standing Electromagnetic Waves
Electromagnetic waves can be reflected; the surface of a conductor or a dielectric can act as a reflector. As electric and magnetic fields obey the superposition principle, so do electromagnetic waves. The superposition of an incident wave and a reflected electromagnetic wave produces a standing wave analogous to the standing waves created on a stretched string.
Suppose a sheet of a perfect conductor is placed in the yz-plane, and a linearly polarized electromagnetic wave traveling in the...
Suppose a sheet of a perfect conductor is placed in the yz-plane, and a linearly polarized electromagnetic wave traveling in the...

