関連する実験動画
Updated: May 11, 2026
11:20
Investigation of Early Plasma Evolution Induced by Ultrashort Laser Pulses
Published on: July 2, 2012
巨大な恒星形成銀河におけるブラックホールの急速な成長
D M Alexander1, I Smail, F E Bauer
1Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK. dma@ast.cam.ac.uk
Nature
|April 9, 2005
まとめ
早期のブラックホールの成長は,クエーザル段階に先立ち,遠い銀河の激しい恒星形成とともに起こります. この研究は,観測的証拠を通して,ブラックホールの質量と銀河の球形状の成長を関連付けています.
科学分野:
- 天体物理学 天体物理学
- コスモロジー・コスモロジーとは
- 銀河の進化 銀河の進化 銀河の進化
背景:
- ブラックホールの質量と,近くの銀河の銀河の球形質量との間に強い相関関係がある.
- クエザーは巨大なブラックホールの増殖期を表しますが,激しい恒星形成は欠けています.
- ブラックホールの成長 (10^6-10^8 太陽の質量) が恒星形成と並行して,クワザール形成前の段階が仮定されている.
研究 の 目的:
- ブラックホールの成長のクワザール以前の段階を調査するために.
- 初期の銀河におけるブラックホールと恒星形成の同時発生の観測シグネチャーを特定する.
主な方法:
- 超深度のX線観測を用いた.
- 遠くの (赤道偏移 z > 1) 恒星形成銀河に焦点を当て,サブミリメートルの波長で明るい.
主要な成果:
- これらの遠い銀河のブラックホールは,恒星形成の激しい期間中に,ほぼ連続した成長を示しています.
- このブラックホールの活動は,これらの特定の銀河集団と強く関連しています.
- 観測されたブラックホールの成長は,クワザール前の段階の予測と一致しています.
結論:
- この研究は,初期の明るい銀河のブラックホールと恒星形成の同時発生の証拠を提供します.
- これは,ブラックホールの成長に不可欠なクワザール前の段階の仮説を裏付けている.
- この発見は,ブラックホールと銀河の進化の間の因果関係を強化している.
関連する概念動画
00:57Population Growth
Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.
01:21Schwarzschild Radius and Event Horizon
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 velocity with the...
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 velocity with the...
01:10Detection of Black Holes
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...
01:14Gravitation Between Spherically Symmetric Masses
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.
01:29Exponential Growth
Bacterial populations exhibit exponential growth when conditions such as nutrient availability and temperature are favorable. In this phase, cells reproduce through binary fission, where each cell divides into two identical daughter cells. This process causes the population to double at regular intervals, resulting in a growth rate that is directly proportional to the current number of cells. As the population increases, the number of new cells formed during each generation also grows, creating...
01:26Exponential Equations for Modeling Growth
Exponential models are essential for describing rapid, multiplicative changes in natural systems, such as population growth. When a population doubles at regular intervals, the process can be modeled using a suitable base. For instance, a bacterial culture that doubles every three hours follows the model n(t)=n0⋅2t/3, where n(t) is the population at the time t.A more general model uses the natural base e, especially for continuous growth. This takes the form n(t)=n0⋅ert, where r is the relative...