منابع مشابه
The dust temperature distribution in prestellar cores
We have computed the dust temperature distribution to be expected in a pre–protostellar core in the phase prior to the onset of gravitational instability. We have done this in the approximation that the heating of the dust grains is solely due to the attenuated external radiation field and that the core is optically thin to its own radiation. This permits us to consider non spherically symmetri...
متن کاملMolecular 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 کاملStructure and Stability of Prestellar Cores
Following an approach initially outlined by McKee & Holliman [5], we investigate the structure and stability of dense, starless molecular cloud cores. We model those as spherical clouds in hydrostatic equilibrium and supported against gravity by thermal, turbulent, and magnetic pressure. We determine the gas pressure by solving for thermal equilibrium between heating and cooling, while the turb...
متن کاملA method to measure CO and N2 depletion profiles inside prestellar cores⋆⋆⋆
Context. In the dense and cold prestellar cores, many species freeze out onto grains to form ices. The most conspicuous case is that of CO itself. Only upper limits of this depletion amplitude can be estimated because the CO emission from the external undepleted layers mask the emission of CO left inside the depleted region. The finite signal-to-noise ratio of the observations is another limita...
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: 2020
ISSN: 1538-4357
DOI: 10.3847/1538-4357/ab774d