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Astrophysical Seminar (2 December 2021, 11:00)

Опубликовано: 29/11/2021

The seminar will be held in a mixed mode

1) Speaker: M.S. Kirsanova (INASAN)

Title: “Dark cloud-type chemistry in PDRs with moderate UV field”

Abstract: see Russian version

2) Speaker: A.G. Zhilkin (INASAN)

Title: “Multi-component MHD model of hot jupiter envelopes”

Abstract: A numerical model description of a hot jupiter extended envelope based on the approximation of multi-component magnetic hydrodynamics is presented. The main attention is focused on the problem of implementing the completed MHD stellar wind model. As a result, the numerical model becomes applicable for calculating the structure of the extended envelope of hot jupiters not only in the super-Alfven and sub-Alfven regimes of the stellar wind flow around and in the trans-Alfven regime. The multi-component MHD approximation allows the consideration of changes in the chemical composition of hydrogen-helium envelopes of hot jupiters. The results of calculations show that, in the case of a super-Alfven flow regime, all the previously discovered types of extended gas-dynamic envelopes are realized in the new numerical model. With an increase in magnitude of the wind magnetic field, the extended envelope tends to become more closed. Under the influence of a strong magnetic field of the stellar wind, the envelope matter does not move along the ballistic trajectory but along the magnetic field lines of the wind toward the host star. This corresponds to an additional (sub-Alfvenic) envelope type of hot jupiters, which has specific observational features. In the transient (trans-Alfven) mode, a bow shock wave has a fragmentary nature. In the fully sub-Alfven regime, the bow shock wave is not formed, and the flow structure is shock-less.

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