関連する実験動画
Updated: Aug 9, 2025

10:35
Bringing the Visible Universe into Focus with Robo-AO
Published on: February 12, 2013
19.5K
ビッグバンの600万年後の赤色候補銀河群
Ivo Labbé1, Pieter van Dokkum2, Erica Nelson3
1Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, Victoria, Australia. ilabbe@swin.edu.au.
Nature
|February 22, 2023
まとめ
天文学者はジェームズ・ウェブ宇宙望遠鏡を用いてビッグバンから7億5千万年以内に,太陽の質量1011に達する可能性のある6つの候補銀河を発見した. この発見は 初期の銀河の質量密度が かつて考えられていたよりも 高いことを示しています
科学分野:
- 宇宙学
- 銀河の形成 と 進化
- 観測天文学
背景:
- 巨大な銀河 (恒星質量 ~1011 太陽質量) は,赤偏移 z ~ 6 (約. ビッグバンから10億年
- 初期の宇宙時代の巨大な銀河を特定することは,バルマー断片が赤外線波長 (> 2.5 μm) に移動しているため,困難です.
研究 の 目的:
- 初期の宇宙 (最初の7億5千万年) で,本質的に赤い,巨大な銀河を探すために.
- ジェームズ・ウェブ宇宙望遠鏡 (JWST) の 1~5ミクロの波長範囲を利用してこの探査を行う.
主な方法:
- ジェームズ・ウェブ宇宙望遠鏡からの早期観測を活用した.
- 1~5μmの波長範囲にフォーカスして,赤にシフトしたバルマー・ブレイクを捉える.
- 特定の調査領域内の 候補の大量銀河を探した.
主要な成果:
- 赤い偏移7.4 ≤ z ≤ 9.1 (約10太陽質量) の6つの候補の大量銀河を特定した. ビッグバンから5億から7億年).
- 一つの候補銀河は,太陽の質量 ~ 10 ~ 11 の潜在的な恒星質量を示しています.
- これらの発見は,JWSTの1〜5μmのスペクトルカバーに基づいています.
結論:
- これらの巨大な銀河の存在は,初期の銀河の恒星質量密度が以前に推定されたよりもかなり高いことを示唆しています.
- これらの結果は 初期の銀河の形成と進化の既存のモデルに 異議を唱えます
- これらの候補星の質量と赤偏移を確認するには,スペクトル検査が必要です.
関連する概念動画
Detection of Black Holes
2.2K
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...
2.2K
Schwarzschild Radius and Event Horizon
2.1K
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...
2.1K
Space-Time Curvature and the General Theory of Relativity
2.9K
In 1905, Albert Einstein published his special theory of relativity. According to this theory, no matter in the universe can attain a speed greater than the speed of light in a vacuum, which thus serves as the speed limit of the universe.
This has been verified in many experiments. However, space and time are no longer absolute. Two observers moving relative to one another do not agree on the length of objects or the passage of time. The mechanics of objects based on Newton's laws of...
This has been verified in many experiments. However, space and time are no longer absolute. Two observers moving relative to one another do not agree on the length of objects or the passage of time. The mechanics of objects based on Newton's laws of...
2.9K
Red Algae
80
Red algae, also known as rhodophytes, are primarily found in marine environments, though some species inhabit freshwater and terrestrial ecosystems. These organisms exist in both unicellular and multicellular forms, with some multicellular varieties reaching macroscopic sizes.As phototrophic organisms, red algae contain chlorophyll a; however, their chloroplasts lack chlorophyll b. Instead, they possess phycobiliproteins, which serve as major light-harvesting pigments, similar to those found in...
80
Gravitation Between Spherically Symmetric Masses
958
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.
958
The Principle of Superposition and the Gravitational Field
1.4K
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...
1.4K

