相关实验视频
Updated: Mar 20, 2026

07:46
Setting Limits on Supersymmetry Using Simplified Models
Published on: November 15, 2013
9.0K
抑制超大质量黑洞风的静止星系中的恒星形成
Edmond Cheung1, Kevin Bundy1, Michele Cappellari2
1Kavli Institute for the Physics and Mathematics of the Universe (World Premier International Research Center Initiative), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583, Japan.
Nature
|May 27, 2016
概括
在典型的静止星系中,从低亮度活跃的星系核中推断出中心驱动的风. 这些风拥有足够的能量来加热气体并抑制恒星形成,解释星系的进化.
科学领域:
- 天体物理学
- 银河系的演变
- 活动的星系核
背景情况:
- 静止星系是由最小的恒星形成所定义的,构成了大多数大质量星系 (>2x10^10太阳质量).
- 静止星系的数量随着宇宙时间的推移而显著增加,
- 现有理论表明超大质量黑洞活动或气体加热机制是导致恒星形成的原因,但典型星系中缺乏直接证据.
研究的目的:
- 在静止的星系中关闭恒星形成的机制.
- 确定典型静止星系中中心驱动的风的观测证据.
- 为了确定低亮度活跃的星系核能否提供抑制恒星形成的能量.
主要方法:
- 在静止的星系中观察双对称的发射特征.
- 对电离气的速度梯度进行分析.
- 来自低亮度活跃超大质量黑洞的能量输出计算.
主要成果:
- 在典型静止星系中检测二对称的发射特征与离子化气体的速度梯度.
- 来自低亮度活核的中心驱动风的推断.
- 证明这些活跃核的能量足以加热周围气体并抑制恒星形成.
结论:
- 来自低亮度活跃星系核的中心驱动的风是静止星系中常见的现象.
- 通过抑制恒星形成, 这些风在调节星系进化中起着至关重要的作用.
- 这些发现为星系进入静止状态的关键机制提供了直接的观测证据.
相关概念视频
Detection 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
Schwarzschild Radius and Event Horizon
2.9K
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...
2.9K
Gravitation Between Spherically Symmetric Masses
1.5K
The gravitational potential energy between two spherically symmetric bodies can be calculated from the masses and the distance between the bodies, assuming that the center of mass is concentrated at the respective centers of the bodies.
1.5K
Reduced Mass Coordinates: Isolated Two-body Problem
2.5K
In classical mechanics, the two-body problem is one of the fundamental problems describing the motion of two interacting bodies under gravity or any other central force. When considering the motion of two bodies, one of the most important concepts is the reduced mass coordinates, a quantity that allows the two-body problem to be solved like a single-body problem. In these circumstances, it is assumed that a single body with reduced mass revolves around another body fixed in a position with an...
2.5K
Kepler's First Law of Planetary Motion
6.0K
In the early 17th century, German astronomer and mathematician Johannes Kepler postulated three laws for the motion of planets in the solar system. He formulated his first two laws based on the observations of his forebears, Nikolaus Copernicus and Tycho Brahe.
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
Polish astronomer Nikolaus Copernicus put forth a theory that stated a heliocentric model for the solar system. According to this heliocentric theory, all the planets, including Earth, orbit the Sun in circular orbits.
On the other hand,...
6.0K
The Principle of Superposition and the Gravitational Field
2.2K
The principle of superposition applies to gravitational forces of objects that are sufficiently far apart. It states that the net gravitational force on a point object is the vector sum of the gravitational forces on it due to various objects. The principle helps calculate the force by listing the individual forces and then vectorially summing them up. However, it should be noted that the principle of superposition is not always apparent. In the presence of a second force, the first force could...
2.2K

