English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present radial velocities, stellar parameters, and detailed abundances of39 elements derived from high-resolution spectroscopic observations of redgiant stars in the luminous, metal-poor globular cluster NGC 5824. We observe26 stars in NGC 5824 using the Michigan/Magellan Fiber System (M2FS) and twostars using the Magellan Inamori Kyocera Echelle (MIKE) spectrograph. We derivea mean metallicity of [Fe/H]=-1.94+/-0.02 (statistical) +/-0.10 (systematic).The metallicity dispersion of this sample of stars, 0.08 dex, is in agreementwith previous work and does not exceed the expected observational errors.Previous work suggested an internal metallicity spread only when faintersamples of stars were considered, so we cannot exclude the possibility of anintrinsic metallicity dispersion in NGC 5824. The M2FS spectra reveal a largeinternal dispersion in [Mg/Fe], 0.28 dex, which is found in a few otherluminous, metal-poor clusters. [Mg/Fe] is correlated with [O/Fe] andanti-correlated with [Na/Fe] and [Al/Fe]. There is no evidence for internaldispersion among the other alpha- or Fe-group abundance ratios. Twenty-five ofthe 26 stars exhibit a n-capture enrichment pattern dominated by r-processnucleosynthesis ([Eu/Fe]=+0.11+/-0.12; [Ba/Eu]=-0.66+/-0.05). Only one starshows evidence of substantial s-process enhancement ([Ba/Fe]=+0.56+/-0.12;[Ba/Eu]=+0.38+/-0.14), but this star does not exhibit other characteristicsassociated with s-process enhancement via mass-transfer from a binarycompanion. The Pb and other heavy elements produced by the s-process suggest atimescale of no more than a few hundred Myr for star formation and chemicalenrichment, like the complex globular clusters M2, M22, and NGC 5286.

Detailed Chemical Abundances in NGC 5824: Another Metal-Poor Globular Cluster with Internal Heavy Element Abundance Variations