EDP Sciences logo
Subscriber Authentication Point
Search
Menu
Home All issues Volume 662 (June 2022) A&A, 662 (2022) C3 Full HTML
Open Access
Erratum
This article is an erratum for:
[https://doi.org/10.1051/0004-6361/202040170]

Issue
A&A
Volume 662, June 2022
Article Number C3
Number of page(s) 2
Section Stellar structure and evolution
DOI https://doi.org/10.1051/0004-6361/202040170e
Published online 28 June 2022

Erratum for: A&A 648, A119 (2021), https://doi.org/10.1051/0004-6361/202040170

We noticed that the dilution factors, f, reported in Table 2 of our paper (Choplin et al. 2021) were wrongly estimated. The new values, as provided in Table 1 of this erratum, are significantly larger than initially reported. We now find 0.68 <  f <  0.98, while in our original paper values of 0.15 <  f <  0.26 were quoted. The agreement between models and observation (in terms of chemical abundances) is not affected by the new values of the dilution factor, as seen in Table 1, where the updated χ ν , min 2 $ \chi_{\rm \nu,min}^2 $ do not differ by more than 3 % from the previous values.

Table 1.

Characteristics and fit parameters of the 14 selected r/s stars.

The only impact of this change is in the discussion of Sect. 6.5. In this section, we linked the dilution factor, f, to physical quantities related to the binary system properties (Eq. (10)),

f = M env M env + M acc = M env M env + β M wind , $$ f = \frac{M_{\rm env}}{M_{\rm env}+M_{\rm acc}} = \frac{M_{\rm env}}{M_{\rm env}+\beta M_{\rm wind}}, $$

where Menv is the envelope mass of the r/s star before the accretion episode, Macc the mass accreted by the r/s star from the asymptotic giant branch (AGB) companion, Mwind the mass lost by the AGB star during its lifetime, and β the accretion efficiency parameter. We highlighted that for f ≃ 0.2, the amount of mass that must be accreted (Macc) to account for the enrichment exceeds 1 M⊙ for giant stars with deep convective envelopes (Menv ≳ 0.4 M⊙). These giants represent 11 out of the 14 selected r/s stars, and the problem was that reaching such high values of Macc cannot be physically achieved by wind accretion (Roche lobe overflow from an AGB star as a means to pollute the binary companion is unlikely as this process will most likely lead to a common envelope evolution).

With the updated values of f (higher by a factor of 4 − 5), the 11 giant stars now have 0.75 <  f <  0.98, which leads to a much more reasonable accreted mass of 8 × 10−3 <  Macc/M⊙ <  0.125 with a mean of 0.06 M⊙. The accretion efficiency parameter, β, now ranges between 0.015 and 0.25 for giant stars. This is compatible with 3D hydrodynamical simulations of wind mass transfer in AGB binary systems (e.g. Saladino et al. 2019).

Overall, the correction of the dilution factors yields morerealistic accreted mass and accretion efficiency parameters. It gives more credit to the AGB wind accretion scenario for explaining the high level of enrichment noticed in most r/s stars. Therefore, this gives even more confidence in low-metallicity AGB stars as a viable site for i-process nucleosynthesis.

References

  1. Aoki, W., Norris, J. E., Ryan, S. G., Beers, T. C., & Ando, H. 2002, ApJ, 567, 1166 [Google Scholar]
  2. Aoki, W., Frebel, A., Christlieb, N., et al. 2006, ApJ, 639, 897 [Google Scholar]
  3. Aoki, W., Beers, T. C., Christlieb, N., et al. 2007, ApJ, 655, 492 [NASA ADS] [CrossRef] [Google Scholar]
  4. Barbuy, B., Spite, M., Spite, F., et al. 2005, A&A, 429, 1031 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]
  5. Choplin, A., Siess, L., & Goriely, S. 2021, A&A, 648, A119 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]
  6. Cohen, J. G., Christlieb, N., Qian, Y. Z., & Wasserburg, G. J. 2003, ApJ, 588, 1082 [Google Scholar]
  7. Cohen, J. G., Christlieb, N., Thompson, I., et al. 2013, ApJ, 778, 56 [Google Scholar]
  8. Cui, W., Shi, J., Geng, Y., et al. 2013, Ap&SS, 346, 477 [Google Scholar]
  9. Hansen, T., Hansen, C. J., Christlieb, N., et al. 2015, ApJ, 807, 173 [Google Scholar]
  10. Ivans, I. I., Sneden, C., Gallino, R., Cowan, J. J., & Preston, G. W. 2005, ApJ, 627, L145 [Google Scholar]
  11. Johnson, J. A., & Bolte, M. 2004, ApJ, 605, 462 [Google Scholar]
  12. Jonsell, K., Barklem, P. S., Gustafsson, B., et al. 2006, A&A, 451, 651 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]
  13. Karinkuzhi, D., Van Eck, S., Goriely, S., et al. 2021, A&A, 645, A61 [EDP Sciences] [Google Scholar]
  14. Lai, D. K., Bolte, M., Johnson, J. A., & Lucatello, S. 2004, AJ, 128, 2402 [Google Scholar]
  15. Lai, D. K., Johnson, J. A., Bolte, M., & Lucatello, S. 2007, ApJ, 667, 1185 [Google Scholar]
  16. Masseron, T., Johnson, J. A., Plez, B., et al. 2010, A&A, 509, A93 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]
  17. Placco, V. M., Frebel, A., Beers, T. C., et al. 2013, ApJ, 770, 104 [Google Scholar]
  18. Roederer, I. U., Preston, G. W., Thompson, I. B., et al. 2014, AJ, 147, 136 [Google Scholar]
  19. Saladino, M. I., Pols, O. R., & Abate, C. 2019, A&A, 626, A68 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]
  20. Sivarani, T., Bonifacio, P., Molaro, P., et al. 2004, A&A, 413, 1073 [NASA ADS] [CrossRef] [EDP Sciences] [Google Scholar]

© A. Choplin et al. 2022

Licence Creative CommonsOpen Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

This article is published in open access under the Subscribe-to-Open model. Subscribe to A&A to support open access publication.

All Tables

Table 1.

Characteristics and fit parameters of the 14 selected r/s stars.

In the text

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.