Bibcode
Monelli, M.; Walker, A. R.; Martínez-Vázquez, C. E.; Stetson, P. B.; Gallart, C.; Bernard, E. J.; Bono, G.; Vivas, A. K.; Andreuzzi, G.; Dall'Ora, M.; Fiorentino, G.; Dorta, A.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 479, Issue 4, p.4279-4291
Advertised on:
10
2018
Citations
13
Refereed citations
11
Description
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.
Related projects
Galaxy Evolution in the Local Group
Galaxy formation and evolution is a fundamental Astrophysical problem. Its study requires “travelling back in time”, for which there are two complementary approaches. One is to analyse galaxy properties as a function of red-shift. Our team focuses on the other approach, called “Galactic Archaeology”. It is based on the determination of galaxy
Matteo
Monelli