Authors 
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Document type 
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Communication à un colloque (Conference Paper) 
Abstract 
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This work presents a new hydrodynamical algorithm to study astrophysical detonations. A prime motivation of this development is the description of a carbon detonation in conditions relevant to superbursts, which are thought to result from the propagation of a detonation front around the surface of a neutron star in the carbon layer underlying the atmosphere.
Methods.The algorithm we have developed is a finitevolume method inspired by the original MUSCL scheme of van Leer (1979). The algorithm is of secondorder in the smooth part of the flow and avoids dimensional splitting. It is applied to some test cases, and the timedependent results are compared to the corresponding steady state solution.
Results.Our algorithm proves to be robust to test cases, and is considered to be reliably applicable to astrophysical detonations. The preliminary onedimensional calculations we have performed demonstrate that the carbon detonation at the surface of a neutron star is a multiscale phenomenon. The length scale of liberation of energy is 106 times smaller than the total reaction length. We show that a multiresolution approach can be used to solve all the reaction lengths. This result will be very useful in future multidimensional simulations. We present also thermodynamical and composition profiles after the passage of a detonation in a pure carbon or mixed carboniron layer, in thermodynamical conditions relevant to superbursts in pure helium accretor systems. 
Language 
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Anglais 
Conference 
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"10th International Symposiumon Origin of Matter and Evolution of Galaxies", APS, Sapporo, Japan (du 04/12/2007 au 07/12/2007) 
Affiliation 
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UCL
 FSA/MECA  Département de mécanique

Keywords 
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Hydrodynamics ; Nuclear reactions ; Nucleosynthesis ; Abundances ; Shock waves ; Stars: neutron ; Xrays: bursts

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