Next Article in Journal
Stochastic Gravitational-Wave Backgrounds: Current Detection Efforts and Future Prospects
Next Article in Special Issue
Ionization-Gasdynamic Simulations of Wind-Blown Nebulae around Massive Stars
Previous Article in Journal / Special Issue
A Preliminary Investigation of CSPN in the HASH Database
Article

DEATHSTAR—CO Envelope Size and Asymmetry of Nearby AGB Stars

1
Theoretical Astrophysics, Division for Astronomy and Space Physics, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden
2
Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
*
Author to whom correspondence should be addressed.
Academic Editors: Martín Guerrero, Noam Soker and Quentin A. Parker
Galaxies 2022, 10(1), 33; https://doi.org/10.3390/galaxies10010033
Received: 7 January 2022 / Revised: 3 February 2022 / Accepted: 8 February 2022 / Published: 12 February 2022
(This article belongs to the Special Issue Asymmetric Planetary Nebulae 8e)
Low- and intermediate-mass stars evolve into asymptotic giant branch (AGB) stars near the end of their lives, losing mass through slow and massive winds. The ejected material creates a chemically-rich expanding envelope around the star, namely the circumstellar envelope (CSE). Investigating the anisotropy of the mass-loss phenomenon on the AGB is crucial in gaining a better understanding of the shaping of the CSE during the transition from AGB star to planetary nebula (PN). We investigate possible signs of deviation from spherical symmetry in the CO-emitting CSEs of 70 AGB stars by analysing their emission maps in CO J=21 and 32 observed with the Atacama Compact Array, as part of the DEATHSTAR project. We find that about one third of the sources are likely aspherical, as they exhibit large-scale asymmetries that are unlikely to have been created by a smooth wind. Further high-resolution observations would be necessary to investigate the nature of, and the physical processes behind, these asymmetrical structures. View Full-Text
Keywords: AGB stars; mass loss; outflows; circumstellar matter AGB stars; mass loss; outflows; circumstellar matter
Show Figures

Figure 1

MDPI and ACS Style

Andriantsaralaza, M.; Vlemmings, W.; Ramstedt, S.; De Beck, E. DEATHSTAR—CO Envelope Size and Asymmetry of Nearby AGB Stars. Galaxies 2022, 10, 33. https://doi.org/10.3390/galaxies10010033

AMA Style

Andriantsaralaza M, Vlemmings W, Ramstedt S, De Beck E. DEATHSTAR—CO Envelope Size and Asymmetry of Nearby AGB Stars. Galaxies. 2022; 10(1):33. https://doi.org/10.3390/galaxies10010033

Chicago/Turabian Style

Andriantsaralaza, Miora, Wouter Vlemmings, Sofia Ramstedt, and Elvire De Beck. 2022. "DEATHSTAR—CO Envelope Size and Asymmetry of Nearby AGB Stars" Galaxies 10, no. 1: 33. https://doi.org/10.3390/galaxies10010033

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop