The short-lived production of exozodiacal dust in the aftermath of a dynamical instability in planetary systems (MNRAS, 2013)

• Sean Raymond

Full Citation:
Bonsor, A., Raymond, S. N., & Augereau, J.-C. (2013). The short-lived production of exozodiacal dust in the aftermath of a dynamical instability in planetary systems. Monthly Notices of the Royal Astronomical Society, 433(4), 2938–2945. https://doi.org/10.1093/mnras/stt933

Abstract:
Excess emission, associated with warm, dust belts, commonly known as exozodis, has been observed around a third of nearby stars. The high levels of dust required to explain the observations are not generally consistent with steady-state evolution. A common suggestion is that the dust results from the aftermath of a dynamical instability, an event akin to the Solar system's Late Heavy Bombardment. In this work, we use a data base of N-body simulations to investigate the aftermath of dynamical instabilities between giant planets in systems with outer planetesimal belts. We find that, whilst there is a significant increase in the mass of material scattered into the inner regions of the planetary system following an instability, this is a short-lived effect. Using the maximum lifetime of this material, we determine that even if every star has a planetary system that goes unstable, there is a very low probability that we observe more than a maximum of 1 per cent of sun-like stars in the aftermath of an instability, and that the fraction of planetary systems currently in the aftermath of an instability is more likely to be limited to ≤0.06 per cent. This probability increases marginally for younger or higher mass stars. We conclude that the production of warm dust in the aftermath of dynamical instabilities is too short-lived to be the dominant source of the abundantly observed exozodiacal dust.

URL:
https://academic.oup.com/mnras/article/433/4/2938/1748771

VPL Research Tasks:
Task C: The Habitable Planet