Affiliation:
1. Observatório do Valongo, Universidade Federal do Rio de Janeiro , Ladeira do Pedro Antônio 43, 20080-090 Rio de Janeiro, Brazil
2. Instituto de Astrofísica de La Plata , CCT La Plata-CONICET-UNLP, Paseo del Bosque S/N (1900), La Plata, Argentina
3. Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata , Paseo del Bosque S/N (1900), La Plata, Argentina
Abstract
ABSTRACT
Hot Jupiters (HJs) are giant planets with orbital periods of the order of a few days with semimajor axis within ∼0.1 au. Several theories have been invoked in order to explain the origin of this type of planets, one of them being the high-eccentricity migration. This migration can occur through different high-eccentricity mechanisms. Our investigation focused on six different kinds of high-eccentricity mechanisms, namely, direct dispersion, coplanar, Kozai–Lidov, secular chaos, E1 and E2 mechanisms. We investigated the efficiency of these mechanisms for the production of HJ candidates in multiplanet systems initially tightly-packed in the semimajor axis, considering a large set of numerical simulations of the exact equations of motion in the context of the N-body problem. In particular, we analyzed the sensitivity of our results to the initial number of planets, the initial semimajor axis of the innermost planetary orbit, the initial configuration of planetary masses, and to the inclusion of general relativity (GR) effects. We found that the E1 mechanism is the most efficient in producing HJ candidates both in simulations with and without the contribution of GR, followed by the Kozai–Lidov and E2 mechanisms. Our results also revealed that, except for the initial equal planetary mass configuration, the E1 mechanism was notably efficient in the other initial planetary mass configurations considered in this work. Finally, we investigated the production of HJ candidates with prograde, retrograde, and alternating orbits. According to our statistical analysis, the Kozai–Lidov mechanism has the highest probability of significantly exciting the orbital inclinations of the HJ candidates.
Funder
Universidade Federal do Rio de Janeiro
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Agencia Nacional de Promoción Científica y Tecnológica
Universidad Nacional de La Plata
Publisher
Oxford University Press (OUP)
Subject
Space and Planetary Science,Astronomy and Astrophysics