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.
Referencia bibliográfica
The Astrophysical Journal, Volume 864, Issue 1, article id. 57, 14 pp. (2018).
Fecha de publicación:
9
2018
Revista
Número de citas
28
Número de citas referidas
27
Descripción
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.
Proyectos relacionados
Evolución Galáctica en el Grupo Local
La formación y evolución de galaxias es un problema fundamental en Astrofísica. Su estudio requiere “viajar atrás en el tiempo”, para lo cual hay dos enfoques complementarios. El mas extendido consiste en analizar las propiedades de las galaxias a diferentes distancias cosmológicas. Nuestro equipo se concentra en el otro enfoque, denominado
Matteo
Monelli