Hiding in the Shadows II: Collisional Dust as Exoplanet Markers

TL;DR

This paper proposes new observational markers based on collisional dust patterns in protoplanetary disks, which can help identify promising exoplanet candidates around young stars, improving detection efficiency.

Contribution

It introduces a novel simulation approach combining N-body dynamics and collision models to identify dust signatures indicative of embedded planets in transitional disks.

Findings

Bright double rings at 850 μm indicate low eccentricity planets.

Inner disk asymmetries suggest high eccentricity planets.

Markers are detectable within planetary gaps in transitional disks.

Abstract

Observations of the youngest planets ($\sim$1-10 Myr for a transitional disk) will increase the accuracy of our planet formation models. Unfortunately, observations of such planets are challenging and time-consuming to undertake even in ideal circumstances. Therefore, we propose the determination of a set of markers that can pre-select promising exoplanet-hosting candidate disks. To this end, N-body simulations were conducted to investigate the effect of an embedded Jupiter mass planet on the dynamics of the surrounding planetesimal disk and the resulting creation of second generation collisional dust. We use a new collision model that allows fragmentation and erosion of planetesimals, and dust-sized fragments are simulated in a post process step including non-gravitational forces due to stellar radiation and a gaseous protoplanetary disk. Synthetic images from our numerical simulations show a bright double ring at 850 $\mu$m for a low eccentricity planet, whereas a high eccentricity planet would produce a characteristic inner ring with asymmetries in the disk. In the presence of first generation primordial dust these markers would be difficult to detect far from the orbit of the embedded planet, but would be detectable inside a gap of planetary origin in a transitional disk.