Three-dimensional instability of flame fronts in type I X-ray bursts
Three-dimensional instability of flame fronts in type I X-ray bursts
We present the first realistic 3D simulations of flame front instabilities during type I X-ray bursts. The unperturbed front is characterized by the balance between the pressure gradient and the Coriolis force of a spinning neutron star (ν = 450 Hz in our case). This balance leads to a fast horizontal velocity field parallel to the flame front. This flow is strongly sheared in the vertical direction. When we perturb the front an instability quickly corrugates the front. We identify this instability as the baroclinic instability. Most importantly, the flame is not disrupted by the instability and there are two major consequences: the overall flame propagation speed is ~10 times faster than in the unperturbed case and distinct flame vortices appear. The speedup is due to the corrugation of the front and the dynamics of the vortices. These vortices may also be linked to the oscillations observed in the light curves of the bursts.
Cavecchi, Yuri
939cba7d-c099-4d5a-a962-1fee916ea176
Spitkovsky, Anatoly
1b454800-83b1-4760-b338-dfc483fcd855
11 September 2019
Cavecchi, Yuri
939cba7d-c099-4d5a-a962-1fee916ea176
Spitkovsky, Anatoly
1b454800-83b1-4760-b338-dfc483fcd855
Cavecchi, Yuri and Spitkovsky, Anatoly
(2019)
Three-dimensional instability of flame fronts in type I X-ray bursts.
The Astrophysical Journal, 882 (2).
(doi:10.3847/1538-4357/ab3650).
Abstract
We present the first realistic 3D simulations of flame front instabilities during type I X-ray bursts. The unperturbed front is characterized by the balance between the pressure gradient and the Coriolis force of a spinning neutron star (ν = 450 Hz in our case). This balance leads to a fast horizontal velocity field parallel to the flame front. This flow is strongly sheared in the vertical direction. When we perturb the front an instability quickly corrugates the front. We identify this instability as the baroclinic instability. Most importantly, the flame is not disrupted by the instability and there are two major consequences: the overall flame propagation speed is ~10 times faster than in the unperturbed case and distinct flame vortices appear. The speedup is due to the corrugation of the front and the dynamics of the vortices. These vortices may also be linked to the oscillations observed in the light curves of the bursts.
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Cavecchi_2019_ApJ_882_142
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Accepted/In Press date: 25 July 2019
Published date: 11 September 2019
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Local EPrints ID: 434393
URI: http://eprints.soton.ac.uk/id/eprint/434393
ISSN: 0004-637X
PURE UUID: ef663cfa-eabf-49e6-aa03-d825df3a20e9
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Date deposited: 23 Sep 2019 16:30
Last modified: 16 Mar 2024 04:17
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Author:
Yuri Cavecchi
Author:
Anatoly Spitkovsky
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