Header

UZH-Logo

Maintenance Infos

Dynamical friction with radiative feedback – II. High-resolution study of the subsonic regime


Velasco Romero, David A; Masset, Frédéric S (2020). Dynamical friction with radiative feedback – II. High-resolution study of the subsonic regime. Monthly Notices of the Royal Astronomical Society, 495(2):2063-2074.

Abstract

Recent work has suggested that the net gravitational force acting on a massive and luminous perturber travelling through a gaseous and opaque medium can have same direction as the perturber’s motion (an effect sometimes called negative dynamical friction). Analytic results were obtained using a linear analysis and were later confirmed by means of non-linear numerical simulations which did not resolve the flow within the Bondi sphere of the perturber, hence effectively restricted to weakly perturbed regions of the flow. Here we present high-resolution simulations, using either 3D Cartesian or 2D cylindrical meshes that resolve the flow within the Bondi sphere. We perform a systematic study of the force as a function of the perturber’s mass and luminosity, in the subsonic regime. We find that perturbers with mass M smaller than a few Mc ∼ χcs/G are subjected to a thermal force with a magnitude in good agreement with linear theory (χ being the thermal diffusivity of the medium, cs the adiabatic sound speed, and G the gravitational constant), while for larger masses, the thermal forces are only a fraction of the linear estimate that decays as M−1. Our analysis confirms the possibility of negative friction (hence a propulsion) on sufficiently luminous, low-mass embryos embedded in protoplanetary discs. Finally, we give an approximate expression of the total force at low Mach number, valid both for subcritical (M < Mc) and supercritical (M > Mc) perturbers.

Abstract

Recent work has suggested that the net gravitational force acting on a massive and luminous perturber travelling through a gaseous and opaque medium can have same direction as the perturber’s motion (an effect sometimes called negative dynamical friction). Analytic results were obtained using a linear analysis and were later confirmed by means of non-linear numerical simulations which did not resolve the flow within the Bondi sphere of the perturber, hence effectively restricted to weakly perturbed regions of the flow. Here we present high-resolution simulations, using either 3D Cartesian or 2D cylindrical meshes that resolve the flow within the Bondi sphere. We perform a systematic study of the force as a function of the perturber’s mass and luminosity, in the subsonic regime. We find that perturbers with mass M smaller than a few Mc ∼ χcs/G are subjected to a thermal force with a magnitude in good agreement with linear theory (χ being the thermal diffusivity of the medium, cs the adiabatic sound speed, and G the gravitational constant), while for larger masses, the thermal forces are only a fraction of the linear estimate that decays as M−1. Our analysis confirms the possibility of negative friction (hence a propulsion) on sufficiently luminous, low-mass embryos embedded in protoplanetary discs. Finally, we give an approximate expression of the total force at low Mach number, valid both for subcritical (M < Mc) and supercritical (M > Mc) perturbers.

Statistics

Citations

Dimensions.ai Metrics
1 citation in Web of Science®
2 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

2 downloads since deposited on 15 Feb 2021
2 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Institute for Computational Science
Dewey Decimal Classification:530 Physics
Scopus Subject Areas:Physical Sciences > Astronomy and Astrophysics
Physical Sciences > Space and Planetary Science
Uncontrolled Keywords:Space and Planetary Science, Astronomy and Astrophysics
Language:English
Date:21 June 2020
Deposited On:15 Feb 2021 10:09
Last Modified:16 Feb 2021 21:00
Publisher:Oxford University Press
ISSN:0035-8711
OA Status:Green
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.1093/mnras/staa1215

Download

Green Open Access

Download PDF  'Dynamical friction with radiative feedback – II. High-resolution study of the subsonic regime'.
Preview
Content: Published Version
Filetype: PDF
Size: 3MB
View at publisher
Licence: Creative Commons: Attribution 4.0 International (CC BY 4.0)