Détail du document
Identifiant
oai:arXiv.org:2406.02682
Sujet
Astrophysics - Earth and Planetary... Astrophysics - Solar and Stellar A...Auteur
Olofsson, Johan Thébault, Philippe Bayo, Amelia Henning, Thomas Milli, JulienCatégorie
sciences : astrophysique
Année
2024
Date de référencement
12/06/2024
Mots clés
light particles observations constrain debris intensity disks astrophysicsRésumé
Debris disks give us the unique opportunity to probe the properties of small $\mu$m-sized particles, allowing us to peer into the constituents of their parent bodies, young analogs of comets and asteroids of our solar system.
In the past, studies of the total intensity phase function have proven powerful to constrain the main characteristics of the dust particles in debris disks.
Nonetheless, there can remain some degeneracies in the modeling that can be alleviated when considering polarized intensity observations.
We obtained new near-IR scattered light observations of four young debris disks which allow us to constrain the degree of linear polarization as a function of the scattering angle.
All four debris disks are detected in polarized intensity, and three are also recovered in total intensity.
We measured peak degree of polarization of $\lesssim 40$\% for all three disks.
We find that the particles must consist of highly refractive and absorbing material.
For HD129590, by measuring the polarization fraction beyond the birth ring, we constrain the width of the size distribution to be smaller and smaller, compatible with the effect of radiation pressure.
We put these findings to the test and present a self-consistent approach to produce synthetic images, assuming different profiles for the radiation pressure strength, and accounting for the presence of unbound grains.
We find the contribution of these grains to be especially critical to reproduce the increasing degree of polarization with stellocentric distances.
Some of our results might seem difficult to reconcile with our understanding of cosmic dust but since similar results have been obtained for other disks, we discuss the current limitation of available light scattering models as well as possible avenues to alleviate these unfortunate limitations.
;Comment: Accepted for publication in A&A, abstract shortened
Olofsson, Johan,Thébault, Philippe,Bayo, Amelia,Henning, Thomas,Milli, Julien, 2024, The near-infrared degree of polarization in debris disks. Toward a self-consistent approach to model scattered light observations
Configurable Safety Tuning of Language Models with Synthetic Preference Data
data preference cst dpo configurable language safety
Affective flexibility as a developmental building block of cognitive reappraisal: An fMRI study
cognitive success affective flexibility
