The extreme initial kinetic energy allowed by a collapsing turbulent core |
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Authors: | Guillermo Arreaga-García |
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Institution: | 1.Departamento de Investigación en Física,Universidad de Sonora,Hermosillo,Mexico |
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Abstract: | We present high-resolution hydrodynamical simulations aimed at following the gravitational collapse of a gas core, in which a turbulent spectrum of velocity is implemented only initially. We determine the maximal value of the ratio of kinetic energy to gravitational energy, denoted here by \((\frac{E_{\mathrm{kin}} }{E_{\mathrm{grav}}} )_{\max}\), so that the core (i) will collapse around one free-fall time of time evolution or (ii) will expand unboundedly, because it has a value of \(\frac{E_{\rm kin}}{E_{\mathrm{grav}}}\) larger than \(( \frac{E_{\mathrm{kin}}}{E_{\mathrm{grav}}} )_{\mathrm{max}}\). We consider core models with a uniform or centrally condensed density profile and with velocity spectra composed of a linear combination of one-half divergence-free turbulence type and the other half of a curl-free turbulence type. We show that the outcome of the core collapse are protostars forming either (i) a multiple system obtained from the fragmentation of filaments and (ii) a single primary system within a long filament. In addition, some properties of these protostars are also determined and compared with those obtained elsewhere. |
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