dc.creator |
Fenner, Y. |
|
dc.creator |
Campbell, S. |
|
dc.creator |
Karakas, A. I. |
|
dc.creator |
Lattanzio, J. C. |
|
dc.creator |
Gibson, Brad K. |
|
dc.date.accessioned |
2013-12-09T18:25:37Z |
|
dc.date.available |
2013-12-09T18:25:37Z |
|
dc.date.issued |
2004 |
|
dc.identifier.issn |
1365-2966 |
|
dc.identifier.uri |
http://library2.smu.ca/xmlui/handle/01/25461 |
|
dc.description |
Publisher's version/PDF |
|
dc.description.abstract |
A self-consistent model of the chemical evolution of the globular cluster NGC 6752 is presented to test a popular theory that observed abundance anomalies are due to ‘internal pollution’ from intermediate-mass asymptotic giant branch stars. We simulated the chemical evolution of the intracluster medium under the assumption that the products of Type II supernovae are completely expelled from the globular cluster, whereas the material ejected from stars with m [less than, approximate to] 7 M[subscript circled dot] is retained, due to their weak stellar winds. By tracing the chemical evolution of the intracluster gas we have tested an internal pollution scenario, in which the Na- and Al-enhanced ejecta from intermediate-mass stars is either accreted on to the surfaces of other stars, or goes toward forming new stars. The observed spread in Na and Al was reproduced, but not the O–Na and Mg–Al anticorrelations. In particular, neither O nor Mg are sufficiently depleted to account for the observations. We predict that the Mg content of Na-rich cluster stars should be overwhelmingly dominated by the [superscript 25,26]Mg isotopes, whereas the latest data show only a mild [superscript 26]Mg enhancement and no correlation with [superscript 25]Mg. Furthermore, stars bearing the imprint of intermediate-mass stellar ejecta are predicted to be strongly enhanced in both C and N, in conflict with the empirical data. We show that the NGC 6752 data are not matched by a model incorporating detailed nucleosynthetic yields from asymptotic giant branch stars. Although these stars do show the hot hydrogen burning that seems to be required to explain the observations, this is accompanied by helium burning, producing primary C, N, Mg and Na (via hot-bottom burning) which do not match the observations. Based on current theories of intermediate-mass stellar nucleosynthesis, we conclude that these stars are not responsible for most of the observed globular cluster abundance anomalies. |
en_CA |
dc.description.provenance |
Submitted by Trish Grelot (trish.grelot@smu.ca) on 2013-12-09T18:25:37Z
No. of bitstreams: 1
karakas_a_i_article_2003.pdf: 204299 bytes, checksum: 1c2bf1685208b13a569efe2e8bb57af4 (MD5) |
en |
dc.description.provenance |
Made available in DSpace on 2013-12-09T18:25:37Z (GMT). No. of bitstreams: 1
karakas_a_i_article_2003.pdf: 204299 bytes, checksum: 1c2bf1685208b13a569efe2e8bb57af4 (MD5)
Previous issue date: 2004-06-15 |
en |
dc.language.iso |
en |
en_CA |
dc.publisher |
Royal Astronomical Society |
en_CA |
dc.publisher |
Oxford University Press |
|
dc.relation.uri |
http://dx.doi.org/10.1111/j.1365-2966.2004.08108.x |
|
dc.rights |
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society
©: 2004 RAS. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
|
dc.subject.lcsh |
Stars -- Globular clusters |
|
dc.subject.lcsh |
Asymptotic giant branch stars |
|
dc.subject.lcsh |
Nucleosynthesis |
|
dc.subject.lcsh |
Cosmic abundances |
|
dc.title |
Modelling self-pollution of globular clusters from asymptotic giant branch stars |
en_CA |
dc.type |
Text |
en_CA |
dcterms.bibliographicCitation |
Monthly Notices of the Royal Astronomical Society 353(3), 789-795. (2004) |
en_CA |