与快速无线电爆发源FRB 121102相关的极端磁离子环境
D Michilli1,2, A Seymour3, J W T Hessels1,2
1ASTRON, Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo, The Netherlands.
Nature
|January 12, 2018
概括
快速无线电爆发 (FRB) 是一种神秘的宇宙信号. FRB 121102表现出极端的极化和动态环境,
科学领域:
- 天体物理学
- 无线电天文学
- 宇宙现象
背景情况:
- 快速无线电爆发 (FRB) 是毫秒的银河系外无线电闪光,来源不明.
- FRB 121102是唯一已知的重复FRB,位于矮星系的恒星形成区域,靠近持久无线电源.
- 电磁波的起源,持续源性和当地的环境仍然不清楚.
研究的目的:
- 为了研究FRB 121102的特性.
- 了解围绕反复发射的极端环境.
- 限制FRB的物理来源及其持久源的性质.
主要方法:
- 使用射电望远镜观测FRB 121102.
- 对偏振特性进行分析,包括法拉第旋转测量.
- 测量时间结构和随时间的变化.
主要成果:
- FRB 121102显示了近百分之百的线性极化.
- 观察到一个非常高且可变的法拉第旋转量 (1.331.46 × 10^5 rad/m2).
- 检测到狭窄的时间结构 (< 30 微秒).
结论:
- 极端和动态的磁离子环境表明FRB 121102靠近一个巨大的黑洞.
- 短爆发时间和高旋转指向中子星的起源.
- 可能的场景包括一个巨大的黑洞环境中的中子星或磁化星云.
相关概念视频
Ionic Bonds
132.5K
Overview
When atoms gain or lose electrons to achieve a more stable electron configuration they form ions. Ionic bonds are electrostatic attractions between ions with opposite charges. Ionic compounds are rigid and brittle when solid and may dissociate into their constituent ions in water. Covalent compounds, by contrast, remain intact unless a chemical reaction breaks them.
Opposing Charges Hold Ions Together in Ionic Compounds
Ionic bonds are reversible electrostatic interactions between ions...
When atoms gain or lose electrons to achieve a more stable electron configuration they form ions. Ionic bonds are electrostatic attractions between ions with opposite charges. Ionic compounds are rigid and brittle when solid and may dissociate into their constituent ions in water. Covalent compounds, by contrast, remain intact unless a chemical reaction breaks them.
Opposing Charges Hold Ions Together in Ionic Compounds
Ionic bonds are reversible electrostatic interactions between ions...
132.5K
Ionic Radii
33.9K
Ionic radius is the measure used to describe the size of an ion. A cation always has fewer electrons and the same number of protons as the parent atom; it is smaller than the atom from which it is derived. For example, the covalent radius of an aluminum atom (1s22s22p63s23p1) is 118 pm, whereas the ionic radius of an Al3+ (1s22s22p6) is 68 pm. As electrons are removed from the outer valence shell, the remaining core electrons occupying smaller shells experience a greater effective nuclear...
33.9K
Molecular and Ionic Solids
20.3K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
20.3K
Solubility of Ionic Compounds
68.4K
Solubility is the measure of the maximum amount of solute that can be dissolved in a given quantity of solvent at a given temperature and pressure. Solubility is usually measured in molarity (M) or moles per liter (mol/L). A compound is termed soluble if it dissolves in water.
68.4K
Ionic Crystal Structures
18.1K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
18.1K
Ionic Compounds: Formulas and Nomenclature
88.2K
An element composed of atoms that readily lose electrons (a metal) can react with an element composed of atoms that readily gain electrons (a nonmetal) to produce ions through complete electron transfer. The compound formed by this transfer is stabilized by the electrostatic attractions (ionic bonds) between the oppositely charged ions.
88.2K


