Temperature influenced dynamics of small dust particles
Authors:
M. Kocifaj
Image & caption:
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Image caption::
Secular time evolution of semimajor axis for carbonaceous particles of different radii orbiting the Sun. Solid curves: dielectric function of carbonaceous particles independent of temperature, dashed curves: real conditions. The particle of the radius 0.6 μm with temperature dependent refractive index (dashed curve) escaped from the solar system 55 years after starting the calculation.
Description:
The dynamics of cosmic dust particles in the gravitational and electromagnetic fields were analyzed theoretically, taking into account the effect of Lorentz force. We have shown that long-term dynamical evolution of particles can be significantly influenced by the varying temperature, if the particles are composed of material whose refractive index is temperature-dependent. It is well known, that temperature quickly decrease as the heliocentric distance increases. Assuming the carbonaceous or Si particles are orbiting the Sun, any small change of their dielectric functions may reduce the lifetime of these particles to a few tens of percent. While the numerical simulations on 2-μm carbon particles show that the inclination of their orbit is greater than the inclination of a parent body, the same calculation made for particles with temperature-dependent refractive index show a significant spread of particles along the orbit of the parent body. Inclination of the particle’s orbit can thereby be smaller than that of parent body. The temperature dependence of the refractive index is therefore responsible for a complex distribution of material along Keplerian orbits. In result, the temperature can separate materials with different temperature profiles of refractive indices.
Reference:
Monthly Notices of the Royal Astronomical Society, Vol. 370 (2006), p. 1876–1884
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