Variable stars in local group galaxies - IV. RR Lyrae stars in the central regions of the low-density galaxy Crater II - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Monthly Notices of the Royal Astronomical Society Year : 2018

Variable stars in local group galaxies - IV. RR Lyrae stars in the central regions of the low-density galaxy Crater II

M. Monelli
A. R. Walker
  • Function : Author
C. E. Martínez-Vázquez
  • Function : Author
P. B. Stetson
  • Function : Author
C. Gallart
  • Function : Author
G. Bono
  • Function : Author
A. K. Vivas
  • Function : Author
G. Andreuzzi
  • Function : Author
M. Dall'Ora
  • Function : Author
G. Fiorentino
A. Dorta
  • Function : Author

Abstract

We present a search and analysis of variable stars in the recently discovered Crater II dwarf galaxy. Based on B, V, I data collected with the Isaac Newton Telescope (FoV∼0.44 deg2), we detected 37 variable stars, of which 34 are bone-fide RR Lyrae stars of Crater II (28 RRab, 4 RRc, 2 RRd). We applied the metal-independent (V, B - V) Period-Wesenheit relation and derived a true distance modulus (μ = 20.30 ± 0.08 mag (σ = 0.16 mag). Individual metallicities for RR Lyrae stars were derived by inversion of the predicted I-band Period-Luminosity relation. We find a mean metallicity of [Fe/H] = -1.64 and a standard deviation of σ _{[Fe/H]}=0.21 dex, compatible with either negligible or vanishing intrinsic metallicity dispersion. The analysis of the colour-magnitude diagram reveals a stark paucity of blue horizontal branch stars, at odds with other Galactic dwarfs, and globular clusters with similar metal abundances.
Fichier principal
Vignette du fichier
sty1645.pdf (1.6 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-03689234 , version 1 (07-06-2022)

Identifiers

Cite

M. Monelli, A. R. Walker, C. E. Martínez-Vázquez, P. B. Stetson, C. Gallart, et al.. Variable stars in local group galaxies - IV. RR Lyrae stars in the central regions of the low-density galaxy Crater II. Monthly Notices of the Royal Astronomical Society, 2018, 479, pp.4279-4291. ⟨10.1093/mnras/sty1645⟩. ⟨insu-03689234⟩
23 View
17 Download

Altmetric

Share

Gmail Facebook X LinkedIn More