Bibcode
Magurno, D.; Sneden, C.; Braga, V. F.; Bono, G.; Mateo, M.; Persson, S. E.; Dall’Ora, M.; Marengo, M.; Monelli, M.; Neeley, J. R.
Bibliographical reference
The Astrophysical Journal, Volume 864, Issue 1, article id. 57, 14 pp. (2018).
Advertised on:
9
2018
Journal
Citations
28
Refereed citations
27
Description
We present a detailed spectroscopic analysis of horizontal branch stars
in the globular cluster NGC 3201. We collected optical (4580–5330
Å), high-resolution (∼34,000), high signal-to-noise ratio
(∼200) spectra for 11 RR Lyrae stars and one red horizontal branch
star with the multifiber spectrograph M2FS with the 6.5 m Magellan
telescope at the Las Campanas Observatory. From measured equivalent
widths, we derived atmospheric parameters and abundance ratios for
α (Mg, Ca, and Ti), iron-peak (Sc, Cr, Ni, and Zn), and s-process
(Y) elements. We found that NGC 3201 is a homogeneous, monometallic
([Fe/H] = ‑1.47 ± 0.04), α-enhanced ([α/Fe] =
0.37 ± 0.04) cluster. The relative abundances of the iron-peak
and s-process elements were found to be consistent with solar values. In
comparison with other large stellar samples, NGC 3201 RR Lyraes have
similar chemical enrichment histories as do those of other old (t ≥
10 Gyr) Halo components (globular clusters; red giants; blue and red
horizontal branch stars; and RR Lyraes). We also provided a new average
radial velocity estimate for NGC 3201 by using a template velocity curve
to overcome the limit of single-epoch measurements of variable stars:
Vrad = 494 ± 2 km s‑1 (σ = 8 km
s‑1).
This paper includes data gathered with the 6.5 m Magellan Telescopes
located at Las Campanas Observatory, Chile.
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