AST 111 Lecture Notes - Lecture 29: Accretion Disk, Molecular Cloud, Gravitational Energy
6 Jun 2020
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Document Summary
Provide raw material from which new stars form. At the low temperatures most of the gas is in the form of molecules. More than a 100 other molecules detected. Radio rotational lines can be detected by mm wave telescopes such as mopra telescope. H2 cant be detected but co and other molecules can. Occurs when a portion of cloud begins to collapse under its gravity. Often a cloud will fragment as it collapses, so a group of stars may be formed together. Object formed by collapsing cloud is known as a protostar. Because the dust in molecule clouds absorbs light in the early stages of star formation can"t usually be observed at visible wavelengths. Infrared radiation is better at penetrating dust. Millimeter and submillimeter observations are useful for studying such regions. Initial cloud will have a small amount of rotation. As the cloud collapses, conservation of angular momentum requires that it will spin more rapidly.
