Ford, A.; Jeffries, R.D.; Smalley, B.; Ryan, S.G.; Aoki, W.; Kawanomoto, S.; James, D.J. and Barnes, J.R.
Lithium 6104 Å in Population II stars.
Astronomy and Astrophysics, 393 pp. 617–628.
Full text available as:
We have obtained échelle spectroscopy of 14 Population II objects selected from those previously observed by Bonifacio & Molaro (1997). For one object, HD 140283, we obtained exquisite data with the High Dispersion Spectrograph on the Subaru Telescope, with S/N exceeding 1000 per 0.018 Å pixel. Li abundances have been determined by spectral synthesis from both the 6708 Å resonance line and also from 6104 Å subordinate feature. Firm detections of the weak line have been made in seven objects, and upper limits are reported for the remainder. Our 6708 Å abundances agree with those reported by Bonifacio & Molaro with a mean difference of only 0.019 +/- 0.009 dex. Abundances from the 6104 Å line hint at a higher Li abundance than that determined from the resonance feature, but this evidence is mixed; the weakness of the 6104 Å line and the large number of upper limits make it difficult to draw firm conclusions. NLTE-corrections increase (rather than eliminate) the size of the (potential) discrepancy, and binarity appears unlikely to affect any abundance difference. The effect of multi-dimensional atmospheres on the line abundances was also considered, although it appears that use of 3-D (LTE) models could again act to increase the discrepancy, if one is indeed present.
|Project Funding Details:
|Funded Project Name||Project ID||Funding Body|
|Not Set||Not Set||UK Particle Physics and Astronomy Research Council (PPARC) [grant PPA/0/S/1998/00658]|
||Some of the symbols may not have transferred correctly into this bibliographic record. Article published by EDP Sciences and available at http://www.edpsciences.org/aa or http://dx.doi.org/10.1051/0004-6361:20021040
||stars abundances; Population II; stars interiors
||Science > Physical Sciences
||Users 6827 not found.
||07 Jul 2006
||23 Feb 2016 19:12
|Share this page:
Download history for this item
These details should be considered as only a guide to the number of downloads performed manually. Algorithmic methods have been applied in an attempt to remove automated downloads from the displayed statistics but no guarantee can be made as to the accuracy of the figures.
Actions (login may be required)