Pin-Gao Gu and Takeru K. Suzuki 2009 ApJ 705 1189 doi:10.1088/0004-637X/705/2/1189
Pin-Gao Gu1 and Takeru K. Suzuki2,3
Show affiliationsWe investigate the thermal response of the atmosphere of a solar-type star to an electron beam injected from a hot Jupiter by performing a one-dimensional MHD numerical experiment with nonlinear wave dissipation, radiative cooling, and thermal conduction. In our experiment, the stellar atmosphere is non-rotating and is modeled as a one-dimensional open flux tube expanding super-radially from the stellar photosphere to the planet. An electron beam is assumed to be generated from the reconnection site of the planet's magnetosphere. The effects of the electron beam are then implemented in our simulation as dissipation of the beam momentum and energy at the base of the corona where the Coulomb collisions become effective. When the sufficient energy is supplied by the electron beam, a warm region forms in the chromosphere. This warm region greatly enhances the radiative fluxes corresponding to the temperature of the chromosphere and transition region. The warm region can also intermittently contribute to the radiative flux associated with the coronal temperature due to the thermal instability. However, owing to the small area of the heating spot, the total luminosity of the beam-induced chromospheric radiation is several orders of magnitude smaller than the observed Ca II emissions from HD 179949.
methods: numerical; MHD; planetary systems; stars: atmospheres
Issue 2 (2009 November 10)
Received 2009 January 28, accepted for publication 2009 September 28
Published 2009 October 19
Pin-Gao Gu and Takeru K. Suzuki 2009 ApJ 705 1189
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