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The role of AGB stars in Galactic and cosmic chemical enrichment

Published online by Cambridge University Press:  30 December 2019

Chiaki Kobayashi
Affiliation:
Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, UK email: c.kobayashi@herts.ac.uk
Christopher J. Haynes
Affiliation:
Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, UK email: c.kobayashi@herts.ac.uk
Fiorenzo Vincenzo
Affiliation:
Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, UK email: c.kobayashi@herts.ac.uk
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Abstract

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The role of asymptotic giant branch (AGB) stars in chemical enrichment is significant for producing 12,13C, 14N, F, 25,26Mg, 17O and slow neutron-capture process (s-process) elements. The contribution from super-AGB stars is negligible in classical, one-zone chemical evolution models, but the mass ranges can be constrained through the contribution from electron-capture supernovae and possibly hybrid C+O+Ne white dwarfs, if they explode as Type Iax supernovae. In addition to the recent s-process yields of AGB stars, we include various sites for rapid neutron-capture processes (r-processes) in our chemodynamical simulations of a Milky Way type galaxy. We find that neither electron-capture supernovae or neutrino-driven winds are able to adequately produce heavy neutron-capture elements such as Eu in quantities to match observations. Both neutron-star mergers (NSMs) and magneto-rotational supernovae (MRSNe) are able to produce these elements in sufficient quantities. Using the distribution in [Eu/(Fe, α)] – [Fe/H], we predict that NSMs alone are unable to explain the observed Eu abundances, but may be able to together with MRSNe. In order to discuss the role of long-lifetime sources such as NSMs and AGB stars at the early stages of galaxy formation, it is necessary to use a model that can treat inhomogeneous chemical enrichment, such as in our chemodynamical simulations. In our cosmological, chemodynamical simulations, we succeed in reproducing the observed N/O-O/H relations both for global properties of galaxies and for local inter-stellar medium within galaxies, without rotation of stars. We also predict the evolution of CNO abundances of disk galaxies, from which it will be possible to constrain the star formation histories.

Type
Contributed Papers
Copyright
© International Astronomical Union 2019 

References

Carlos, M., Karakas, A. I., Cohen, J. G., Kobayashi, C., & Meléndez, J. 2018, ApJ, 856, 161 CrossRefGoogle Scholar
Cescutti, G., & Kobayashi, C. 2017, A&A, 607, 23 Google Scholar
Doherty, C. L., Gil-Pons, P., Siess, L., Lattanzio, J. C., & Lau, H. H. B., 2015, MNRAS, 446, 2599 CrossRefGoogle Scholar
Fink, M., et al. 2014, MNRAS, 438, 1762 CrossRefGoogle Scholar
Haynes, C., & Kobayashi, C. 2018, MNRAS, submitted arXiv:1809.10991 (HK18)Google Scholar
Jones, S. Hirschi, R., & Nomoto, K. 2014, ApJ, 797, 83 CrossRefGoogle Scholar
Karakas, A. I., & Lugaro, M., 2016, ApJ, 825, 26 CrossRefGoogle Scholar
Kobayashi, C. 2014, IAU S298, 167 CrossRefGoogle Scholar
Kobayashi, C. 2016, Nature, 540, 205 CrossRefGoogle Scholar
Kobayashi, C., Izutani, N., Karakas, A. I., et al., 2011a, ApJ (Letters), 739, L57 Google Scholar
Kobayashi, C., Karakas, I. A., & Lugaro, M. 2018, in preparationGoogle Scholar
Kobayashi, C., Karakas, I. A., & Umeda, H. 2011b, MNRAS, 414, 3231 (K11)CrossRefGoogle Scholar
Kobayashi, C., & Nakasato, N. 2011, ApJ, 729, 16 CrossRefGoogle Scholar
Kobayashi, C., & Nomoto, K. 2009, ApJ, 707, 1466 CrossRefGoogle Scholar
Kobayashi, C., Nomoto, K., & Hachisu, I. 2015, ApJ (Letters), 804, L24 Google Scholar
Kobayashi, C., Springel, V, & White, S. D. M. 2007, MNRAS, 376, 1465 CrossRefGoogle Scholar
Kobayashi, C., Tsujimoto, T., & Nomoto, K. 2000, ApJ, 539, 26 CrossRefGoogle Scholar
Kobayashi, C., Umeda, H., Nomoto, K., Tominaga, N., & Ohkubo, T. 2006, ApJ, 653, 1145 CrossRefGoogle Scholar
Mennekens, N., & Vanbeveren, D. 2014, A&A, 564, A134 Google Scholar
Nishimura, N., Takiwaki, T., & Thielemann, F.-K. 2015, ApJ, 810, 109 CrossRefGoogle Scholar
Nomoto, K., Kobayashi, C., & Tominaga, N. 2013, ARAA, 51, 457 (N13)CrossRefGoogle Scholar
Pllumbi, E., Tamborra, I., Wanajo, S., Janka, H.-T., & Hüdepohl, L. 2015, ApJ, 808, 188 CrossRefGoogle Scholar
Scannapieco, C. et al. 2012, MNRAS, 423, 1726 CrossRefGoogle Scholar
Taylor, P., & Kobayashi, C. 2015, MNRAS, 448, 1835 CrossRefGoogle Scholar
Vincenzo, F., & Kobayashi, C. 2018a, A&A, 610, L16 (VK18a)Google Scholar
Vincenzo, F., & Kobayashi, C. 2018b, MNRAS, 478, 155 (VK18b)CrossRefGoogle Scholar
Vincenzo, F., & Kobayashi, C. 2019, IAU FM7, in pressGoogle Scholar
Wanajo, S., 2013, ApJ (Letters), 770, L22 Google Scholar
Wanajo, S., Janka, H.-T., & Müller, B., 2013, ApJ (Letters), 767, L26 Google Scholar
Wanajo, S., Sekiguchi, Y., Nishimura, et al. 2014, ApJ (Letters), 789, L39 Google Scholar