関連する実験動画
Updated: Apr 14, 2026
11:47
A 100 KW Class Applied-field Magnetoplasmadynamic Thruster
Published on: December 22, 2018
9.8K
アクティブな銀河です. 超大質量ブラックホールのジェットベースにある強力な磁場
Ivan Martí-Vidal1, Sébastien Muller2, Wouter Vlemmings2
1Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Space Observatory, SE-43992, Onsala, Sweden. mivan@chalmers.se.
Science (New York, N.Y.)
|April 18, 2015
まとめ
研究者は,アタカマの大型ミリメートル/サブミリメートル配列 (ALMA) を使用して,活発な銀河核 (AGN) ジェット (ジェット) の底部で強い磁場を検出しました. この発見は,これらの強力な宇宙ジェットがどのように形成され,導かれるのかについての新しい洞察を提供します.
科学分野:
- 天体物理学 天体物理学
- 宇宙磁場は,宇宙の磁場である.
- アクティブな銀河核 (AGN)
背景:
- 活発な銀河核 (AGN) は,超大質量ブラックホールに物質の蓄積によって動いている.
- AGNからの流出ジェットはエネルギー現象ですが,その形成および誘導機構は不明です.
- 磁場は,AGNジェット形成とコリマーションにおいて重要な役割を果たしていると考えられています.
研究 の 目的:
- AGNジェットの形成とコリマーションにおける磁場の役割を調査する.
- AGNジェットの底部にある磁場を検知し,特徴づけること.
主な方法:
- アタカマの大型ミリメートル/サブミリメートル配列 (ALMA) を使用して,遠いAGN PKS 1830-211を観測しました.
- ポラライゼーション信号,特にファラデー回転が検出され,磁場の存在を示す.
- 視線に沿った磁場強度と電子密度の積分に比例する回転の尺度を測定しました.
主要な成果:
- AGN PKS 1830-211.のジェットベースで有意な偏振信号 (ファラデー回転) が検出されました.
- 強い磁場の存在を示唆する高回転測定を導出しました.
- 暗示された磁場強度は,ブラックホールから約光日 (0.01パーセック) のスケールで少なくとも数十ガウスである.
結論:
- AGNジェットの底部には強い磁場がある.
- これらの磁場は,活発な銀河核から観測される強力なジェットの形成と誘導に重要な役割を果たしている可能性が高い.
- この発見は,AGNジェットの磁気起源を支持する直接的な証拠を提供します.
関連する概念動画
01:10Detection of Black Holes
2.6K
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
2.6K
01:21Schwarzschild Radius and Event Horizon
3.0K
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape...
3.0K
01:19Magnetic Field Lines
6.6K
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:
6.6K
01:27Magnetic Fields
8.0K
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
8.0K
01:23Magnetic Field due to Moving Charges
12.6K
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
12.6K
01:24Energy In A Magnetic Field
3.0K
If a magnetic field is sustained, there must be a current in a closed circuit or loop, implying some energy has been spent in creating the field. If this energy is not dissipated via the circuit's resistance, it is stored in the field.
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...
Take an ideal inductor with zero resistance. Although it's practically impossible, assume that the coil's resistance is so small that it is practically negligible. The loss of the field's energy to dissipate thermal energy (or heat) is thus...
3.0K