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Figure 1:
UVES spectra of the two turn-off stars 200613 and 4428 of
the GC NGC 6752. The dotted lines correspond to the
Be abundances
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Figure 2: UVES spectra of stars 200613 and 4428 around the NH band at 336 nm. The band is much stronger in star 200613, indicating a strong N overabundance. Solid lines are the observed spectra; thin lines are synthetic spectra computed with parameters appropriate to the program stars, and N abundances of [N/Fe] = 0, 0.4, 0.8, 1.2, 1.6 and 2.0. |
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Figure 3:
Evolution of Be with time in the Galaxy according to a
three-zone Galactic chemical evolution model (Valle et al. 2002). The
three curves refer to the halo, thick disk, and thin disk. The data
points show the Be abundance in the young open cluster IC 2391 (age
55 Myr), the Sun (age 4.5 Gyr), the globular clusters NGC 6397
(isochrone age
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Figure 4: Be abundance vs. Fe for the NGC 6397 ( filled circles) and the NGC 6752 TO star ( filled square) and the star from B99 ( open circles). The stars in the clusters are indistinguishable from the field stars. |
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Figure 5: Be abundance vs. O for the NGC 6397 ( filled circles) and the NGC 6752 TO stars ( filled square) and the star from B99 ( open circles). The "unpolluted'', O-rich stars in the clusters closely follow the field stars. |
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