Abundant sub-micron grains revealed in newly discovered extreme debris discs

Autor(en)

Attila Moór, Péter Ábrahám, Kate Y.~L. Su, Thomas Henning, Sebastian Marino, Lei Chen, Ágnes Kóspál, Nicole Pawellek, József Varga, Krisztián Vida

Abstrakt

Extreme debris discs (EDDs) are bright and warm circumstellar dusty structures around main sequence stars. They may represent the outcome of giant collisions occuring in the terrestrial region between large planetesimals or planetary bodies, and thus provide a rare opportunity to peer into the aftermaths of these events. Here, we report on results of a mini-survey we conducted with the aim to increase the number of known EDDs, investigate the presence of solid-state features around 10 μm in eight EDDs, and classify them into the silica or silicate dominated groups. We identify four new EDDs and derive their fundamental properties. For these, and for four other previously known discs, we study the spectral energy distribution around 10 μm by means of VLT/VISIR photometry in three narrow-band filters and conclude that all eight objects likely exhibit solid-state emission features from submicron grains. We find that four discs probably belong to the silicate dominated subgroup. Considering the age distribution of the entire EDD sample, we find that their incidence begins to decrease only after 300 Myr, suggesting that the earlier common picture that these objects are related to the formation of rocky planets may not be exclusive, and that other processes may be involved for older objects (≿100 Myr). Because most of the older EDD systems have wide, eccentric companions, we suggest that binarity may play a role in triggering late giant collisions.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

HUN-REN Research Centre for Astronomy and Earth Sciences, Eötvös Loránd University Budapest, University of Arizona, Max-Planck-Institut für Astronomie, University of Exeter

Journal

MNRAS

Band

528

Seiten

4528-4546

Anzahl der Seiten

19

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/stae155

Publikationsdatum

03-2024

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/7ab20af7-5a35-47ab-84e6-d33da61234e6