Boron in the Extreme Pop II Star HD 140283 and the Production of Light Elements in the Early Galaxy
In: Astron. Astrophys. 290 (1994) 176; (1994)
Online
report
Zugriff:
Using observations of the 2496.7 A B I line with the HST GHRS at a nominal resolution of 90,000, we have found the abundance of boron of HD 140283 to be log epsilon_B (= 12 + log (N_B/N_H)) = 0.34 \pm 0.20. This result is found when a significant non-LTE effect in the formation of the B I line is taken into account. The resulting N_B/N_Be ratio is about 17 (in the range 9 -- 34), which is in very good agreement with what is expected from spallation by cosmic rays. We conclude that this origin of Be and B in the Early Galaxy is the most probable of recently suggested formation mechanisms. (Submitted to A&A. Postscript figures available via annymous ftp to "chiron.astro.uu.se" in directory pub/Preprints/P87)
Comment: 6 pages, A&A plain TeX, UAO-94-P87
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Boron in the Extreme Pop II Star HD 140283 and the Production of Light Elements in the Early Galaxy
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| Autor/in / Beteiligte Person: | Edvardsson, B. ; Gustafsson, B. ; Johansson, S. G. ; Kiselman, D. ; Lambert, D. L. ; Nissen, P. E. ; Gilmore, G. |
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| Quelle: | Astron. Astrophys. 290 (1994) 176; (1994) |
| Veröffentlichung: | 1994 |
| Medientyp: | report |
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