Sublimation Temperature of Circumstellar Dust Particles and Its Importance for Dust Ring Formation

TL;DR

This paper analytically investigates how the sublimation temperature of circumstellar dust influences dust ring formation, emphasizing its critical role over optical properties in dust pile-up near stars.

Contribution

It introduces analytical formulae for dust sublimation location and temperature, highlighting the importance of sublimation temperature in dust ring formation.

Findings

High sublimation temperature dust forms significant rings near stars.

Sublimation temperature impacts the size of dust-free zones.

Analytical formulas aid in detecting sublimation evidence in observations.

Abstract

Dust particles in orbit around a star drift toward the central star by the Poynting-Robertson effect and pile up by sublimation. We analytically derive the pile-up magnitude, adopting a simple model for optical cross sections. As a result, we find that the sublimation temperature of drifting dust particles plays the most important role in the pile-up rather than their optical property does. Dust particles with high sublimation temperature form a significant dust ring, which could be found in the vicinity of the sun through in-situ spacecraft measurements. While the existence of such a ring in a debris disk could not be identified in the spectral energy distribution (SED), the size of a dust-free zone shapes the SED. Since we analytically obtain the location and temperature of sublimation, these analytical formulae are useful to find such sublimation evidences.