The formation of stellar systems from interstellar molecular clouds.
نویسندگان
چکیده
Star formation, a crucial link in the chain of events that led from the early expansion of the universe to the formation of the solar system, continues to play a major role in the evolution of many galaxies. Observational and theoretical studies of regions of ongoing star formation provide insight into the physical conditions and events that must have attended the formation of the solar system. Such investigations also elucidate the role played by star formation in the evolutionary cycle which appears to dominate the chemical processing of interstellar material by successive generations of stars in spiral galaxies like our own. New astronomical facilities planned for development during the 1980's could lead to significant advances in our understanding of the star formation process. Efforts to identify and examine both the elusive protostellar collapse phase of star formation and planetary systems around nearby stars will be especially significant.
منابع مشابه
Interstellar Media in the Magellanic Clouds and other Local Group Dwarf Galaxies
I review the properties of the interstellar medium in the Magellanic Clouds and Local Group dwarf galaxies. The more massive, star-forming galaxies show a complex, multi-phase ISM full of shells and holes ranging from very cold phases (a few 10 K) to extremely hot gas (> 10 K). In environments with high UV radiation fields the formation of molecular gas is suppressed, while in dwarfs with low U...
متن کاملThe Evolution of Molecular Clouds
Molecular clouds constitute the densest parts of the interstellar medium in galaxies, and ever since their discovery 25 years ago they have been of prime interest as the sites of star formation. Molecular clouds also play an important galactic role in that massive stars recently formed in them provide the main energy sources for the interstellar medium, partly by destroying their birth clouds a...
متن کاملIn Dust We Trust: an Overview of Observations and Theories of Interstellar Dust
The past century of interstellar dust has brought us from first ignoring it to finding that it is an important component of the interstellar medium and plays an important role in the evolution of galaxies, the formation of stars and planetary systems, and possibly, the origins of life. Current observational results in our galaxy provide a complex physical and chemical evolutionary picture of in...
متن کاملThe Excitation of Molecular Clouds and the Emission from Molecular Hydrogen
The observation and theory of UV{excitation of molecular clouds (i.e., photodissociation regions) and the shock-excitation of molecular clouds is reviewed, with particular emphasis placed on the emission from molecular hydrogen. Recent advances in near{IR instrumentation have engendered new observations which are challenging our theoretical understanding of these fundamental physical processes....
متن کاملThe chemistry of interstellar space
Interstellar space is not empty, but contains gaseous and particulate matter that is concentrated into very large regions known as interstellar clouds. In the denser and cooler clouds, the gas is molecular and most of the molecules detected are organic in nature. The gas-phase molecules are synthesised from precursor atoms by rapid exothermic reactions in the gas and on the surfaces of tiny dus...
متن کاملChemistry in Dense Molecular Clouds: Theory and Observational Constraints
For the most part, gas phase models of the chemistry of dense molecular clouds predict the abundances of simple species rather well. However, for larger molecules and even for small systems rich in carbon these models often fail spectacularly. We present a brief review of the basic assumptions and results of large scale modeling of the chemistry in dense molecular clouds. Particular attention w...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Science
دوره 224 4651 شماره
صفحات -
تاریخ انتشار 1984