arXiv subjects

Nathaniel W. H. Moore

Publications and source records attributed to Nathaniel W. H. Moore.

3 recordsLinked to original sources

arXiv2024

Main-sequence systems: orbital stability around single star hosts

Stability is one of the most fundamental aspects regarding planetary systems. It plays an important role in our understanding on the formation channel of the planetary systems, as well as their habitability. Many approaches have been adopted to determine the stability of these systems, including brute-force N-body simulations, semi-analytical calculations, and more recently machine learning methods. This allows significant advances in our understanding of planetary system dynamics, as well as providing tools to constrain unknown parameters of exoplanetary systems (assuming these systems are stable). In the following, we focus on planets around single star hosts, and we provide an overview of the studies of planetary system stability for compact multi-planet systems and hierarchical multi-planet systems.

astro-ph.EP↗

arXiv2022

Formation History of HD106906 and the Vertical Warping of Debris Disks by an External Inclined Companion

HD106906 is a planetary system that hosts a wide-orbit companion, as well as an eccentric and flat debris disk, which hold important constraints on its formation and subsequent evolution. The recent observations of the companion constrain its orbit to be eccentric and inclined relative to the plane of the debris disk. Here, we show that, in the presence of the inclined companion, the debris disk quickly ($\lesssim5$ Myr) becomes warped and puffy. This suggests that the current configuration of the system is relatively recent. We explore the possibility that a recent close encounter with a free floating planet could produce a companion with orbital parameters that agree with observations of HD106906b. We find that this scenario is able to recreate the structure of the debris disk while producing a companion in agreement with observation.

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arXiv2020

Inclination Excitation of Solar System Debris Disk due to Stellar Flybys

Most stars form in clusters where relatively close encounters with other stars are common and can leave imprints on the orbital architecture of planetary systems. In this paper, we investigate the inclination excitation of debris disk particles due to such stellar encounters. We derive an analytical expression that describes inclination excitation in the hierarchical limit where the stellar flyby is distant. We then obtain numerical results for the corresponding particle inclination distribution in the non-hierarchical regime using a large ensemble of N-body simulations. For encounters with expected parameters, we find that the bulk inclination of the disk particles remains low. However, a distinct high inclination population is produced by prograde stellar encounters for particles with final pericenter distances above $50$AU. The maximum extent $i_t$ of the inclination distribution scales with the inclination of the encounter $\sin(i_s)$ for massive star flybys with low incoming velocity. The inclination distribution of observed trans-Neptunian objects places constraints on the dynamical history of our Solar System. For example, these results imply an upper limit on product of the number density $n$ of the solar birth cluster and the Sun's residence time $τ$ of the form $nτ\lesssim8\times10^4$ Myr pc$^{-3}$. Stronger constraints can be derived with future observational surveys of the outer Solar System.

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