Molecular Evolution in Collapsing Prestellar Cores
نویسندگان
چکیده
منابع مشابه
Molecular Evolution in Collapsing Prestellar Cores
We have investigated the evolution and distribution of molecules in collapsing prestellar cores via numerical chemical models, adopting the Larson-Penston solution and its delayed analogues to study collapse. Molecular abundances and distributions in a collapsing core are determined by the balance among the dynamical, chemical and adsorption time scales. When the central density nH of a prestel...
متن کاملMolecular Evolution in Collapsing Prestellar Cores II: The Effect of Grain-surface Reactions
The molecular evolution that occurs in collapsing prestellar cores is investigated. To model the dynamics, we adopt the Larson-Penston solution and analogues with slower rates of collapse. For the chemistry, we utilize the new standard model (NSM) with the addition of deuterium fractionation and grain-surface reactions treated via the modified rate approach. The use of surface reactions disting...
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The gravitational collapse of a spherical cloud core is investigated by numerical calculations. The initial conditions of the core lie close to the critical BonnorEbert sphere with a central density of ∼ 10 cm in one model (α = 1.1), while gravity overwhelms pressure in the other (α = 4.0), where α is the internal gravity-to-pressure ratio. The α = 1.1 model shows reasonable agreement with the ...
متن کاملMolecular evolution in star-forming cores: From prestellar cores to protostellar cores
We investigate the molecular abundances in protostellar cores by solving the gasgrain chemical reaction network. As a physical model of the core, we adopt a result of onedimensional radiation-hydrodynamics calculation, which follows the contraction of an initially hydrostatic prestellar core to form a protostellar core. Temporal variation of molecular abundances is solved in multiple infalling ...
متن کاملThe Formation and Evolution of Prestellar Cores
Improving our understanding of the initial conditions and earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We review the properties of low-mass dense cores as derived from recent millimeter/submillimeter observations of nearby molecular clouds and discuss them in the context of various contemporary scenar...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2001
ISSN: 0004-637X,1538-4357
DOI: 10.1086/320551