Bibcode
Martell, S. L.; Shetrone, Matthew D.; Lucatello, Sara; Schiavon, Ricardo P.; Mészáros, Szabolcs; Allende Prieto, C.; García Hernández, D. A.; Beers, Timothy C.; Nidever, David L.
Bibliographical reference
The Astrophysical Journal, Volume 825, Issue 2, article id. 146, pp. (2016).
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7
2016
Journal
Citations
80
Refereed citations
76
Description
We present new identifications of five red giant stars in the Galactic
halo with chemical abundance patterns that indicate they originally
formed in globular clusters. Using data from the Apache Point
Observatory Galactic Evolution Experiment (APOGEE) Survey available
through Sloan Digital Sky Survey (SDSS) Data Release 12, we first
identify likely halo giants, and then search those for the well-known
chemical tags associated with globular clusters, specifically enrichment
in nitrogen and aluminum. We find that 2% of the halo giants in our
sample have this chemical signature, in agreement with previous results.
Following the interpretation in our previous work on this topic, this
would imply that at least 13% of halo stars originally formed in
globular clusters. Recent developments in the theoretical understanding
of globular cluster formation raise questions about that interpretation,
and we concede the possibility that these migrants represent a small
fraction of the halo field. There are roughly as many stars with the
chemical tags of globular clusters in the halo field as there are in
globular clusters, whether or not they are accompanied by a much larger
chemically untaggable population of former globular cluster stars.