原始的な原星周りの円盤の形成と断片化
Paul C Clark1, Simon C O Glover, Rowan J Smith
1Institut für Theoretische Astrophysik, Zentrum für Astronomie der Universität Heidelberg, Albert-Ueberle-Str. 2, 69120 Heidelberg, Germany. pcc@ita.uni-heidelberg.de
Science (New York, N.Y.)
|February 5, 2011
まとめ
宇宙の最初の星は,以前信じられていたように単一ではなく,しばしば密接な複数のシステムの一部でした. 円盤の重力分裂により,これらの初期の二重星系と高次元の星系が形成された可能性が高い.
科学分野:
- 天文学と天体物理学について
- コスモロジー・コスモロジーとは
- 恒星の進化について
背景:
- 最初の星の形成は,宇宙の暗黒時代の終わりを象徴した.
- 以前のモデルでは,これらの巨大な恒星が暗黒物質のミニハロースの中で単独または広い二重星で形成されたと考えられていた.
- 初期の恒星形成の性質は,宇宙の後の進化に大きな影響を与えた.
研究 の 目的:
- 宇宙で形成された最初の恒星の多重性を調査するために.
- 孤独な最初の星形成の支配的な概念に挑戦するために.
- 初期の恒星系の形成を制御するメカニズムを理解する.
主な方法:
- 暗黒物質のミニハロース内の初期の恒星形成の数値シミュレーション.
- プロトステラディスクにおける重力分裂過程の分析.
- バイナリーシステムと高次元のシステム形成のモデリング.
主要な成果:
- シミュレーションは,最初の星は,多くの場合,緊密な複数のシステムで形成されたことを示しています.
- これらの初期の恒星の周りの原始恒星円盤は,重力的に不安定でした.
- この不安定さは,断片化につながり,密接に詰め込まれているバイナリと高次元のシステムを生み出しました.
結論:
- 最初の星は,以前の仮定に反して,一般的に複数の星系のメンバーでした.
- 蓄積円盤の重力分裂は,これらの初期の多重系を形成するための重要なメカニズムでした.
- これらの発見は,初期の宇宙構造の形成と進化についての私たちの理解を再構築します.
関連する概念動画
01:33Cleavage and Blastulation
After a large-single-celled zygote is produced via fertilization, the process of cleavage occurs while zygotes travel through the uterine tube. Cleavage is a mitotic cell division that does not result in growth. With each round of successive cell division, daughter cells get increasingly smaller.
01:22Formation of the Platelet Plug
The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...
02:06Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
02:06Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
00:59Mechanisms of Membrane Domain Formation
Different physical properties of lipids and proteins allow them to localize and form distinct islands or domains in the membrane. Some membrane domains are formed due to protein-protein interactions, whereas others are formed due to the presence of specific lipids such as sphingolipids and sterols—for example, large proteins, such as bacteriorhodopsin, aggregate and create distinct domains.
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
Another mechanism for membrane domain formation involves membrane proteins interacting with cytoskeletal...
01:20Mass Spectrometry: Molecular Fragmentation Overview
The ionization of a molecule into a molecular ion inside the mass spectrometer causes instability in the molecule's structure due to the loss of an electron. This eventually leads to the fragmentation or breaking of some bonds in the molecule. The fragmentation occurs predominantly at specific bonds to yield relatively stable fragments.
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...