銀河の84ミクロGの磁場は,赤道偏移 z = 0.692の銀河にある
Arthur M Wolfe1, Regina A Jorgenson, Timothy Robishaw
1Department of Physics and Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, California 92093-0424, USA. awolfe@ucsd.edu
Nature
|October 4, 2008
まとめ
この研究は,遠い銀河の強い磁場を測定し,初期の宇宙におけるより弱い磁場を予測する理論に挑戦した. この発見は,銀河の磁場進化に関する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
- コスミック・マグネティズム (宇宙磁気) とは
- 銀河の進化について
背景:
- 銀河の磁場は,星間媒体の動力学,宇宙線エネルギー,星形成に不可欠である.
- パルサーのファラデー回転を用いた以前の測定では,銀河の磁場が~3マイクロガウスで推定された.
- 初期の銀河 (z > 0) の磁場の強さと赤道移転は不明のままである.
研究 の 目的:
- 赤道偏移 z = 0.692.2 で銀河の磁場強さを測定する.
- 宇宙時間における銀河磁場の進化を調査する.
- 磁場生成のための平均フィールドダイナモモデルの予測をテストする.
主な方法:
- 磁場強度を測定するためにゼーマン分裂技術を使用した.
- 私たちの銀河の中性星間ガスの磁場を決定するために使用される同じ方法を適用しました.
主要な成果:
- およそ84マイクロガウスの磁場が,赤道偏移z = 0.692.2の銀河で測定されました.
- この測定されたフィールドは,我々の銀河の中性ガスで見つかった平均6マイクロガウスよりもかなり強い.
結論:
- この発見は,予期せぬほど磁場強度が,以前の宇宙時代の平均場ダイナモモデルによって予測されたよりも高いことを示している.
- これは,銀河の磁場が過去に必ずしも弱かったわけではないことを示唆している.
- この結果は,磁場発生と銀河の進化の現在のモデルに異議を唱えている.
関連する概念動画
Magnetic Fields
6.0K
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...
6.0K
Magnetic Field Of A Current Loop
6.1K
Consider a circular loop with a radius a, that carries a current I. The magnetic field due to the current at an arbitrary point P along the axis of the loop can be calculated using the Biot-Savart law.
6.1K
Magnetic Field due to Moving Charges
11.3K
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...
11.3K
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
Magnetic Field Due to Two Straight Wires
5.2K
Consider two parallel straight wires carrying a current of 10 A and 20 A in the same direction and separated by a distance of 20 cm. Calculate the magnetic field at a point "P2", midway between the wires. Also, evaluate the magnetic field when the direction of the current is reversed in the second wire.
5.2K
Magnetostatic Boundary Conditions
1.9K
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...
1.9K


