The metallicity distribution in the core of the Sagittarus dwarf spheroidal: Minimising the metallicity biases - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Astronomy and Astrophysics - A&A Year : 2023

The metallicity distribution in the core of the Sagittarus dwarf spheroidal: Minimising the metallicity biases

Alice Minelli
  • Function : Author
Michele Bellazzini
  • Function : Author
Alessio Mucciarelli
  • Function : Author
Donatella Romano
  • Function : Author
Lorenzo Monaco
  • Function : Author
Emanuele Dalessandro
  • Function : Author
Raffaele Pascale
  • Function : Author

Abstract

We present the metallicity and radial velocity for 450 bona fide members of the Sagittarius dwarf spheroidal (Sgr dSph) galaxy, measured from high-resolution spectra (R ≃ 18 000) obtained with FLAMES at the VLT. The targets were carefully selected (a) to sample the core of the main body of Sgr dSph while avoiding contamination from the central stellar nucleus, and (b) to prevent any bias on the metallicity distribution by selecting targets based on their Gaia parallax and proper motions. All the targets selected in this way were confirmed as radial velocity members. We used this sample to derive the first metallicity distribution of the core of Sgr dSph, which is virtually unaffected by metallicity biases. The observed distribution ranges from [Fe/H] ≃ −2.3 to [Fe/H] ≃ 0.0, with a strong, symmetric, and relatively narrow peak around [Fe/H] ≃ −0.5 and a weak and extended metal-poor tail, in which only 13.8 ± 1.9% of the stars have [Fe/H] < −1.0. We confirm previous evidence of correlations between chemical and kinematical properties of stars in the core of Sgr. In our sample, stars with [Fe/H] ≥ −0.6 display a lower velocity dispersion and a higher rotation amplitude than those with [Fe/H] < −0.6, confirming previous suggestions of disk/halo structure for the progenitor of the system.

Full Table 1 is only available at the CDS via anonymous ftp to cdsarc.cds.unistra.fr (ftp://130.79.128.5) or via https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/669/A54

Based on observations collected at the ESO-VLT under programs 105.20AH.001.

Fichier principal
Vignette du fichier
aa44890-22.pdf (2.44 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

insu-03932154 , version 1 (10-01-2023)

Licence

Attribution

Identifiers

Cite

Alice Minelli, Michele Bellazzini, Alessio Mucciarelli, Piercarlo Bonifacio, Rodrigo Ibata, et al.. The metallicity distribution in the core of the Sagittarus dwarf spheroidal: Minimising the metallicity biases. Astronomy and Astrophysics - A&A, 2023, 669, ⟨10.1051/0004-6361/202244890⟩. ⟨insu-03932154⟩
34 View
35 Download

Altmetric

Share

Gmail Facebook X LinkedIn More