From Dust to Nanodust: Resolving Circumstellar Dust from the Colliding-Wind Binary Wolf-Rayet (WR) 140

作     者：Lau, Ryan M. Wang, Jason Hankins, Matthew J. Currie, Thayne Deo, Vincent Endo, Izumi Guyon, Olivier Han, Yinuo Jones, Anthony P. Jovanovic, Nemanja Lozi, Julien Moffat, Anthony F.J. Onaka, Takashi Ruane, Garreth Sander, Andreas A.C. Tinyanont, Samaporn Tuthill, Peter G. Weigelt, Gerd Williams, Peredur M. Vievard, Sebastien 

作者机构：NSF’s NOIRLab 950 N. Cherry Ave. TucsonAZ85719 United States Institute of Space & Astronautical Science Japan Aerospace Exploration Agency 3-1-1 Yoshinodai Chuo-ku Kanagawa Sagamihara252-5210 Japan  Northwestern University 1800 Sherman Ave EvanstonIL60208 United States Department of Physical Sciences Arkansas Tech University 1701 N. Boulder Avenue RussellvilleAR72801 United States Subaru Telescope National Astronomical Observatory of Japan 650 North A‘ohoku Place HiloHI96720 United States Department of Astronomy School of Science University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Steward Observatory University of Arizona TucsonAZ85721 United States Astrobiology Center of NINS 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Institute of Astronomy University of Cambridge Madingley Road CambridgeCB3 0HA United Kingdom Institut d’Astrophysique Spatiale CNRS Univ. Paris-Sud Université Paris-Saclay Bât. 121 OrsayCedex 91405 France Department of Astronomy California Institute of Technology PasadenaCA91125 United States Département de Physique Université de Montréal C.P. 6128 succ. centre-ville MontréalQCH3C 3J7 Canada Centre de Recherche en Astrophysique du Québec Canada Department of Physics Faculty of Science and Engineering Meisei University 2-1-1 Hodokubo Hino Tokyo191-8506 Japan Zentrum für Astronomie der Universität Heidelberg Astronomisches Rechen-Institut Mönchhofstr. 12-14 Heidelberg69120 Germany Department of Astronomy and Astrophysics University of California 1156 High St. Santa CruzCA95064 United States  School of Physics The University of Sydney NSW2006 Australia Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 Bonn53121 Germany Institute for Astronomy University of Edinburgh Royal Observatory EdinburghEH9 3HJ United Kingdom 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2023年

核心收录：

主　　题：Dust 

摘      要：Wolf-Rayet (WR) 140 is the archetypal periodic dust-forming colliding-wind binary that hosts a carbon-rich WR (WC) star and an O-star companion with an orbital period of 7.93 years and an orbital eccentricity of 0.9. Throughout the past several decades, multiple dust-formation episodes from WR 140 have been observed that are linked to the binary orbit and occur near the time of periastron passage. Given its predictable dust-formation episodes, WR 140 presents an ideal astrophysical laboratory for investigating the formation and evolution of dust in the hostile environment around a massive binary system. In this paper, we present near- and mid-infrared (IR) spectroscopic and imaging observations of WR 140 with Subaru/SCExAO+CHARIS, Keck/NIRC2+PyWFS, and Subaru/COMICS taken between 2020 June and Sept that resolve the circumstellar dust emission linked to its most recent dust-formation episode in 2016 Dec. Our spectral energy distribution (SED) analysis of WR 140’s resolved circumstellar dust emission reveals the presence of a hot (Td ∼ 1000 K) near-IR dust component that is co-spatial with the previously known and cooler (Td ∼ 500 K) mid-IR dust component composed of 300–500 Å-sized dust grains. We attribute the hot near-IR dust emission to the presence of nano-sized (nanodust) grains and suggest they were formed from grain-grain collisions or the rotational disruption of the larger grain size population by radiative torques in the strong radiation field from the central binary. Lastly, we speculate on the astrophysical implications of nanodust formation around colliding-wind WC binaries, which may present an early source of carbonaceous nanodust in the interstellar medium. © 2023, CC BY.