عنوان مجله
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ASTROPHYSICS AND SPACE SCIENCE
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چکیده
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The aim of this study is to investigate the evolution of the dust-to-gas ratio in the self-similar collapse of a filamentary
molecular cloud. For this purpose, we use single fluid dusty-gas model in our study, which describes a single fluid moving
with the barycentric velocity of the mixture instead of two-fluid method. The self-similar technique is used to consider the
problem in two phases of the collapse, i.e. isothermal and polytropic collapse phases. Regarding the analytical methods,
we obtain a semi-analytical solution for the dust-to-gas ratio as a function of the barycentric velocity at large radii of the
filament. Furthermore, the polytropic collapse is solved numerically at large radii of a collapsing filamentary cloud. The
results show that the profile of dust-to-gas ratio is very different for the isothermal and polytropic cases. This issue suggests
that thermodynamic processes during the collapse have the most significant effect on the evolution of the dust-to-gas ratio.
It was also proved that the intrinsic density and the grain size play important roles on the values of the dust-to-gas ratio
during the self-similar collapse. Finally, the results address some outstanding issues about the dust distribution during the
gravitational collapse (either the isothermal and adiabatic collapse) which has not received much attention before.
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