The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here: https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

HE

Heitor Ernandes

Postdoctoral fellow

HE

Light elements Na and Al in 58 bulge spheroid stars from APOGEE

Author

  • B. Barbuy
  • A. C.S. Friaça
  • H. Ernandes
  • T. Moura
  • T. Masseron
  • K. Cunha
  • V. V. Smith
  • D. Souto
  • A. Prez-Villegas
  • S. O. Souza
  • C. Chiappini
  • A. B.A. Queiroz
  • J. G. Fernández-Trincado
  • P. Da Silva
  • B. X. Santiago
  • F. Anders
  • R. P. Schiavon
  • M. Valentini
  • D. Minniti
  • D. Geisler
  • V. M. Placco
  • M. Zoccali
  • M. Schultheis
  • C. Nitschelm
  • T. C. Beers
  • R. Razera
Show all

Summary, in English

We identified a sample of 58 candidate stars with metallicity [Fe/H]-0.8 that likely belong to the old bulge spheroid stellar population, and analyse their Na and Al abundances from Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra. In a previous work, we inspected APOGEE-Stellar Parameter and Chemical Abundance Pipeline abundances of C, N, O, Mg, Al, Ca, Si, and Ce in this sample. Regarding Na lines, one of them appears very strong in about 20 per cent of the sample stars, but it is not confirmed by other Na lines, and can be explained by sky lines, which affect the reduced spectra of stars in a certain radial velocity range. The Na abundances for 15 more reliable cases were taken into account. Al lines in the H band instead appear to be very reliable. Na and Al exhibit a spread in abundances, whereas no spread in N abundances is found, and we found no correlation between them, indicating that these stars could not be identified as second-generation stars that originated in globular clusters. We carry out the study of the behaviour of Na and Al in our sample of bulge stars and literature data by comparing them with chemodynamical evolution model suitable for the Galactic bulge. The Na abundances show a large spread, and the chemodynamical models follow the main data, whereas for aluminum instead, the models reproduce very satisfactorily the nearly secondary-element behaviour of aluminum in the metallicity range below [Fe/H]-1.0. For the lower-metallicity end ([Fe/H <-2.5), hypernovae are assumed to be the main contributor to yields.

Department/s

  • Department of Geology

Publishing year

2023-12-01

Language

English

Pages

2365-2376

Publication/Series

Monthly Notices of the Royal Astronomical Society

Volume

526

Issue

2

Document type

Journal article

Publisher

Oxford University Press

Topic

  • Astronomy, Astrophysics and Cosmology

Keywords

  • Galaxy: Abundances
  • Galaxy: bulge
  • Galaxy: evolution
  • stars: Abundances

Status

Published

ISBN/ISSN/Other

  • ISSN: 0035-8711