Non-monotonic spatial distribution of the interstellar dust in astrospheres: finite gyroradius effect

作者：Katushkina O A^*; Alexashov D B; Izmodenov V V; Gvaramadze V V

来源：Monthly Notices of the Royal Astronomical Society, 2017, 465(2): 1573-1585.

DOI：10.1093/mnras/stw2833

• shock waves
• methods: numerical
• circumstellar matter
• dust, extinction

High-resolution mid-infrared observations of astrospheres show that many of them have filamentary (cirrus-like) structure. Using numerical models of dust dynamics in astrospheres, we suggest that their filamentary structure might be related to specific spatial distribution of the interstellar dust around the stars, caused by a gyrorotation of charged dust grains in the interstellar magnetic field. Our numerical model describes the dust dynamics in astrospheres under an influence of the Lorentz force and assumption of a constant dust charge. Calculations are performed for the dust grains with different sizes separately. It is shown that non-monotonic spatial dust distribution (viewed as filaments) appears for dust grains with the period of gyromotion comparable with the characteristic time-scale of the dust motion in the astrosphere. Numerical modelling demonstrates that the number of filaments depends on charge-to-mass ratio of dust.

• 出版日期2017-2