Protostars and Planets VI, Heidelberg, July 15-20, 2013
Simulating Photoevaporative Mass Loss from Hot Jupiters in 3D
Tripathi, Anjali (Harvard-Smithsonian Center for Astrophysics)
Kratter, Kaitlin (JILA/University of Colorado, Boulder)
Krumholz, Mark (University of California, Santa Cruz)
Murray-Clay, Ruth (Harvard-Smithsonian Center for Astrophysics)
Escaping planetary winds have been observed with UV transmission spectra from several transiting hot Jupiters. To find other observational signatures of these winds, we are developing a global model of atmospheric escape from hot Jupiters. Our goal is to model the full, asymmetric structure of the wind, which is driven by photoionizing stellar flux and shaped by stellar winds and orbital motion. This poster presents the current status of our model, which simultaneously includes photoionization heating and is done in three dimensions, unlike previous models.
Using the Athena code for hydrodynamics, we model the planet as a static potential with a hydrostatic atmosphere, at the center of a three-dimensional Cartesian grid. We self-consistently treat the planetary wind\'s production by introducing a planar source of stellar UV flux and evolving it with ionizing radiative transfer coupled to the hydrodynamics. We have implemented our ionization algorithm to include Static Mesh Refinement (SMR) and parallelization with MPI, to resolve the planet\'s exosphere. Tests of the evolution of a planar ionization front in our code match analytic expectations for the propagation rate of a D-type ionization front. Further code development is in progress, and we plan to include the major contributions to the outflow\'s asymmetry - the stellar wind, which can confine the planetary wind structure, and the Coriolis force, which captures the planet\'s orbital motion. Since Athena and our radiative transfer code are compatible with MHD, extensions to the model can further include the planet\'s magnetic field.
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