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==== WP3. 2D structure modelling of rotating stars deformed by the centrifugal force ====


^Responsible |
|Jerôme Ballot |


Compute realistic models of rotating stars deformed by the centrifugal force and provide a grid of models with seismic indices.


=== Tasks ===


    * Compute static 2D models that fit constrains on classical stellar global parameters and seismic indices


As 2D evolution codes do not yet exist, the idea is to derive a grid of 2D models from a grid of 1D evolution models (that take into account rotation effect through 1D modelling) and then to search from this grid the 2D models that best fit the constrains (as the open source tool TOUCAN already does from a 1D model grid). An algorithm to obtain a deformed 2D model from a 1D model has been proposed by I. Roxburgh (2006) and implemented once by R. Ouazzani ([[http://fr.arxiv.org/abs/1301.2496|arXiv:1301.2496)]]. Another possibility is to use the open source code ESTER to compute the static 2D models (ESTER is not yet able to follow the star evolution but can compute a 2D model with a priori constrains on the evolutionary status).


    * An open source version of the TOP code


The TOP code (Reese et al., 2006, Reese et al. 2009, Reese 2013) has  been developped by D. Reese during his Ph.D in Toulouse and has  maintained and improved by him since. It is the first code to accurately  compute oscillation modes without approximating the effects of rotation  on the modes. It played a crucial role to understand the properties of  p-mode and it is still essential for the numerical exploration of  gravito-inertial mode properties (Task2) and linear excitation mechanism  (Task 1). It already served as a benchmark for the development of  another code (ACOR - Ouazzani et al. 2012). For the time being, TOP has  been mainly used to better understand mode properties (WP4) and to  construct seismic analysis tools from synthetic spectra (WP2). With  PERSIA we will make an extensive use of the TOP code to compute seismic  indices for a grid of 2D stellar models (WP3). To further increase its  use and impact in the community, our goal is now to produce and diffuse  an open source version of the TOP code. This task involves a significant  simplification of the code to make it easy to run by non-specialist  users. Then, the code will be diffused through a repository, following  the exemple of the open source ESTER code. This task will be performed  by a computer scientist under the supervision of J. Ballot and D. Reese.


=== Deliverables ===


    * Grid of 2D models including basic seismic indices
    * Tool to compute a 2D centrifugally deformed model fitting a given set of stellar and seismic parameters
    * Open source code to compute oscillation modes of rapidly rotating stars


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