منابع مشابه
The influence of the C + N + O abundances on the determination of the relative ages of Globular Clusters : the case of NGC 1851 and NGC 6121 ( M 4 ) ⋆ †
The color magnitude diagram (CMD) of NGC 1851 presents two subgiant branches (SGB), probably due the presence of two populations differing in total CNO content. We test the idea that a difference in total CNO may simulate an age difference when comparing the CMD of clusters to derive relative ages. We compare NGC 1851 with NGC 6121 (M4), a cluster of very similar [Fe/H]. We find that, with a su...
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متن کاملAbundances of C , N , O in slightly evolved stars in the globular clusters NGC 6397 , NGC 6752 and 47 Tuc ⋆
Abundances of C and N are derived from features due to the CH G-band and to the UV CN band measured on high resolution (R ∼ > 40, 000) UVES spectra of more than 40 dwarfs and subgiants in NGC 6397, NGC 6752 and 47 Tuc. Oxygen abundances (or upper limits) are available for all stars in the sample. Isotopic ratios 12 C/ 13 C were derived from the CH molecular band. This is the first determination...
متن کاملThe C + N + O abundances and the splitting of the subgiant branch in the Globular Cluster NGC 1851
Among the newly discovered features of multiple stellar populations in Globular Clusters, the cluster NGC 1851 harbours a double subgiant branch, that can be explained in terms of two stellar generations, only slightly differing in age, the younger one having an increased total C+N+O abundance. Thanks to this difference in the chemistry, a fit can be made to the subgiant branches, roughly consi...
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در این پژوهش فسفونیک آمیدهای php(o)(nhch2c6h4-4-ch3)2 (1)، php(o)(nhc5h9)2 (2)، php(o)(nc5h9-4-ch3)2 (3) و php(o)(nhc6h4-4-cl)2 (4)، فسفریک تری آمیدهای (4-ch3-c6h4nh)2p(o)(nhc6h4-4-cl) (5)، ((ch3)(c6h11)n)2p(o)(nhc6h4-4-cl) (6)، (oc4h8n)2p(o)(nhc6h4-4-cl) (7)، (4-ch3-c5h9n)2p(o)(nhc6h4-4-cl) (8)، (c3h6)(nh)2p(o)(nhc6h4-4-cl) (9)، (4-ch3-c5h9n)2p(o)(nhc6h4-4-ch3)(10)، p(o)(nhc6h4-4-cl)3 (11)، آم...
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ژورنال
عنوان ژورنال: The Astronomical Journal
سال: 1967
ISSN: 0004-6256
DOI: 10.1086/110436