The chemical compositions of accreted and in situ galactic globular clusters according to SDSS/APOGEE

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Studies of the kinematics and chemical compositions of Galactic globular clusters (GCs) enable the reconstruction of the history of star formation, chemical evolution, and mass assembly of the Galaxy. Using the latest data release (DR16) of the SDSS/APOGEE survey, we identify 3090 stars associated with 46 GCs. Using a previously defined kinematic association, we break the sample down into eight separate groups and examine how the kinematics-based classification maps into chemical composition space, considering only α (mostly Si and Mg) elements and Fe. Our results show that (i) the loci of both in situ and accreted subgroups in chemical space match those of their field counterparts; (ii) GCs from different individual accreted subgroups occupy the same locus in chemical space. This could either mean that they share a similar origin or that they are associated with distinct satelliteswhich underwent similar chemical enrichment histories; (iii) the chemical compositions of the GCs associated with the low orbital energy subgroup defined by Massari and collaborators is broadly consistent with an in situ origin. However, at the low-metallicity end, the distinction between accreted and in situ populations is blurred; (iv) regarding the status of GCs whose origin is ambiguous, we conclude the following: the position in Si-Fe plane suggests an in situ origin for Liller 1 and a likely accreted origin for NGC 5904 and NGC 6388. The case of NGC 288 is unclear, as its orbital properties suggest an accretion origin, its chemical composition suggests it may have formed in situ.

Detaljer

Författare
  • Danny Horta
  • Ricardo P. Schiavon
  • J. Ted MacKereth
  • Timothy C. Beers
  • José G. Fernández-Trincado
  • Peter M. Frinchaboy
  • D. A. García-Hernández
  • Doug Geisler
  • Sten Hasselquist
  • Henrik Jonsson
  • Richard R. Lane
  • Steven R. Majewski
  • Szabolcs Mészáros
  • Christian Moni Bidin
  • David M. Nataf
  • Alexandre Roman-Lopes
  • Christian Nitschelm
  • J. Vargas-González
  • Gail Zasowski
Enheter & grupper
Externa organisationer
  • Liverpool John Moores University
  • University of Birmingham
  • University of Notre Dame
  • University of Atacama
  • Texas Christian University
  • Instituto de Astrofísica de Canarias
  • University of La Laguna (ULL)
  • University of Concepción
  • Universidad de La Serena
  • New Mexico State University
  • University of Utah
  • Pontifical Catholic University of Chile
  • University of Virginia
  • Eötvös Loránd University
  • Johns Hopkins University
  • University of Antofagasta
  • University of Hertfordshire
  • Malmö University
  • Catholic University of the North
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Astronomi, astrofysik och kosmologi
  • Geokemi

Nyckelord

Originalspråkengelska
Sidor (från-till)3363-3378
Antal sidor16
TidskriftMonthly Notices of the Royal Astronomical Society
Volym493
Utgåva nummer3
StatusPublished - 2020 apr
PublikationskategoriForskning
Peer review utfördJa