@article{e25922dbde1345c9a72bc9e9470ba879,
title = "Chemical tracers of a highly eccentric AGB–main-sequence star binary",
abstract = "Binary interactions have been proposed to explain a variety of circumstellar structures seen around evolved stars, including asymptotic giant branch (AGB) stars and planetary nebulae. Studies resolving the circumstellar envelopes of AGB stars have revealed spirals, disks and bipolar outflows, with shaping attributed to interactions with a companion. Here we use a combined chemical and dynamical analysis to reveal a highly eccentric and long-period orbit for W Aquilae, a binary system containing an AGB star and a main-sequence companion. Our results are based on anisotropic SiN emission, the detections of irregular NS and SiC emission towards the S-type star, and density structures observed in the CO emission. These features are all interpreted as having formed during periastron interactions. Our astrochemistry-based method can yield stringent constraints on the orbital parameters of long-period binaries containing AGB stars, and will be applicable to other systems.",
author = "T. Danilovich and J. Malfait and {Van de Sande}, M. and M. Montarg{\`e}s and P. Kervella and {De Ceuster}, F. and A. Coenegrachts and Millar, {T. J.} and Richards, {A. M.S.} and L. Decin and Gottlieb, {C. A.} and C. Pinte and {De Beck}, E. and Price, {D. J.} and Wong, {K. T.} and J. Bolte and Menten, {K. M.} and A. Baudry and {de Koter}, A. and S. Etoka and D. Gobrecht and M. Gray and F. Herpin and M. Jeste and E. Lagadec and S. Maes and I. McDonald and L. Marinho and M{\"u}ller, {H. S.P.} and B. Pimpanuwat and Plane, {J. M.C.} and R. Sahai and Wallstr{\"o}m, {S. H.J.} and J. Yates and A. Zijlstra",
note = "Funding Information: We thank S.-H. Cho of the Korean VLBI Network for KVN observations of W Aql to confirm consistency with our ALMA results. T.D. is supported in part by the Australian Research Council through a Discovery Early Career Researcher Award (DE230100183). T.D., F.D.C. and S.H.J.W. acknowledge support from the Research Foundation Flanders (FWO) through grants 12N9920N, 1253223N and 1285221N, respectively. J.M. and S.M. acknowledge support from the Research Foundation Flanders (FWO) grant G099720N. M.V.d.S. acknowledges support from European Union{\textquoteright}s Horizon 2020 Research and Innovation programme under the Marie Sk{\l}odowska-Curie grant agreement number 882991. M.M. acknowledges funding form the Programme Paris Region fellowship supported by the R{\'e}gion Ile-de-France. P.K. acknowledges funding from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 Research and Innovation programme (synergy grant project UniverScale, grant agreement 951549). T.J.M. is grateful to the STFC for support through grant ST/P000312/1 and thanks the Leverhulme Trust for the award of an Emeritus Fellowship. J.M.C.P. was supported by STFC grant number ST/T000287/1. L.D., J.M.C.P., S.H.J.W., S.M. and D.G. acknowledge support from ERC consolidator grant 646758 AEROSOL. E.D.B. acknowledges support from the Swedish National Space Agency. D.G. was funded by the project grant {\textquoteleft}The Origin and Fate of Dust in Our Universe{\textquoteright} from the Knut and Alice Wallenberg Foundation. K.T.W. acknowledges support from the European Research Council (ERC) under the European Union{\textquoteright}s Horizon 2020 Research and Innovation programme (grant agreement number 883867, project EXWINGS). F.H., A.B. and L.M. acknowledge funding from the French National Research Agency (ANR) project PEPPER (ANR-20-CE31-0002). H.S.P.M. acknowledges support by the Deutsche Forschungsgemeinschaft through the collaborative research grant SFB 956 (project ID 184018867). R.S.{\textquoteright}s contribution to the research described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA, and funded in part by NASA via ADAP awards, and multiple HST GO awards from the Space Telescope Science Institute. A.Z. is funded by STFC/UKRI through grant ST/T000414/1. This research was supported in part by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. This project has received funding from the Framework Program for Research and Innovation {\textquoteleft}Horizon 2020{\textquoteright} under the convention Marie Sk{\l}odowska-Curie No 945298. Computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation Flanders (FWO) and the Flemish Government, department EWI. This research was undertaken with the assistance of resources and services from the National Computational Infrastructure (NCI), which is supported by the Australian Government. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2018.1.00659.L. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 0103.D-0772(A). We acknowledge excellent support from the UK ALMA Regional Centre (UK ARC), which is hosted by the Jodrell Bank Centre for Astrophysics (JBCA) at the University of Manchester. The UK ARC Node is supported by STFC Grant ST/P000827/1. Publisher Copyright: {\textcopyright} 2023, The Author(s), under exclusive licence to Springer Nature Limited.",
year = "2024",
month = jan,
day = "3",
doi = "10.1038/s41550-023-02154-y",
language = "English",
volume = "8",
pages = "308–327",
journal = "Nature Astronomy",
issn = "2397-3366",
publisher = "Nature Publishing Group",
}