Modelling the Formation of Extrasolar Comet Clouds

Autor(en)

Birgit Loibnegger, Nader Haghighipour

Abstrakt

In the last years observations of absorption lines varying on short timescales in spectra of stars accumulate. Scientists refer to these findings as features caused by objects evaporating material on their orbit when they come close to the star and thus call them comets in exoplanetary systems - exocomets. This theory is based on the knowledge about the Solar System. The aim of our dynamical investigation is to find a statistical model for the scattering of small bodies which shows the most probable whereabouts of these objects after the gravitational interaction with the planets. The setup includes a star, a Jupiter-like planet and a disk of planetesimals (testparticles). As a consequence of the migration of the gas giant planetesimals are scattered either inwardor outward. The outward scattered objects will form analogues to the Kuiper belt respectively the Oort Cloud in our Solar System. The created reservoirs are different depending on the initial conditions of the planetesimal disk and the migration of the Jupiter-like planet. Semi-major axis, eccentricity, perihel, aphel, inclination and orbital period after 4byr of integration of each testparticle are measured and statistics are made by comparing the outcomes of the computations withdifferent acting forces applied - as there are gravitational influence of the galactic tide and passing stars. Additionally the influence of the migration of the gas giant on the outcome of the scattering processis examined. In order to apply the described method to extra solarplanetary systems we start with different masses of the central star and different initial conditions for the planet (mass, orbit...) as given from observations. The gained knowledge can be used to generate ageneral model for the formation of cometary reservoirs in extra solarsystems with respect to the system architecture which can be used to predict the location of cometary reservoirs in extrasolar systems.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

University of Hawaii at Manoa

Publikationsdatum

08-2018

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/47202d8b-d957-4cb1-bd9f-cc64884a3b18