関連する実験動画
Updated: May 5, 2026

11:47
A 100 KW Class Applied-field Magnetoplasmadynamic Thruster
Published on: December 22, 2018
8.6K
マグネタールのアンチグリッチ装置
R F Archibald1, V M Kaspi, C-Y Ng
1Department of Physics, McGill University, Montreal, Quebec H3A 2T8, Canada.
Nature
|May 31, 2013
まとめ
マグネタは,高度に磁気化された中性子星で,通常,障害時に回転します. 研究者らは,希少な磁星のスピンダウン"反障害"を観測し,中性子星の行動に関する現在の理論に異議を唱えた.
科学分野:
- 天文学 天文学
- 天体物理学 天体物理学
- 恒星物理学 恒星物理学
背景:
- マグネタは,強力な磁場を持つ中性子星であり,X線とガンマ線の爆発を示します.
- マグネタールやラジオパルサーを含む中性子星は,地殻と超流体内部との間の角運動量移転に起因する突然のスピンアップイベントの"障害"を経験します.
研究 の 目的:
- マグネタール障害の現象を調査し,特に異常なスピンダウンイベントに焦点を当てます.
- 観測されたアンチ・ギッチに関連したX線変数とスピンダウン速度の変化を伴ったX線変数を分析する.
主な方法:
- マグネタール1E 2259+586.6のX線タイミング観測を行った.
- タイミングデータを分析して,スピンダウンイベントと関連する放射性変化を検出し,特徴づけました.
主要な成果:
- マグネタール1E 2259+586で,突然のスピンダウンによって特徴づけられる明確な"アンチ・ギッチ"イベントが観察されました.
- 防障害イベントには,複数のX線放射変化と,マグネタールのスピンダウン速度の大きな変化が伴いました.
結論:
- 観測されたスピンダウン行動は,中性子星のスピンダウンに関する既存のモデルに挑戦しています.
- この事象は,磁星内の微分回転を示唆し,すべての中性子星のためのグリッチ理論の再評価を必要とします.
関連する概念動画
Magnetism
8.2K
Magnets are commonly found in everyday objects, such as toys, hangers, elevators, doorbells, and computer devices. Experimentation on these magnets shows that all magnets have two poles: one is labeled north (N) and the other south (S). Magnetic poles repel if they are alike and attract if unlike. Moreover, both poles of a magnet attract unmagnetized pieces of iron.
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
An individual magnetic pole cannot be isolated. No matter how small, every piece of a magnet contains a north pole and a south...
8.2K
Diamagnetism
2.8K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.8K
Magnetic Flux
4.2K
The magnetic flux measures the number of magnetic field lines passing through a given surface area. The SI unit for magnetic flux is the weber (Wb). Magnetic flux is a scalar quantity. It depends on three factors: the strength of the magnetic field B, the area through which the field lines pass, and the relative orientation of the field with the surface area.
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
Suppose a surface is divided into elements of area dA. For each element, the component of the magnetic field that is normal to the...
4.2K
Paramagnetism
2.4K
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...
2.4K
Potential Due to a Magnetized Object
924
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
The vector...
924
Magnetic Damping
1.3K
Eddy currents can produce significant drag on motion, called magnetic damping. For instance, when a metallic pendulum bob swings between the poles of a strong magnet, significant drag acts on the bob as it enters and leaves the field, quickly damping the motion.
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
1.3K

