Chemical Compositions of Field and Globular Cluster RR Lyrae Stars: I. NGC 3201

Abstract

We present a detailed spectroscopic analysis of horizontal branch stars in the globular cluster NGC 3201. We collected optical (4580-5330 A), high resolution (~34,000), high signal-to-noise ratio (~200) spectra for eleven RR Lyrae stars and one red horizontal branch star with the multifiber spectrograph M2FS at the 6.5m Magellan telescope at the Las Campanas Observatory. From measured equivalent widths we derived atmospheric parameters and abundance ratios for α (Mg, Ca, Ti), iron peak (Sc, Cr, Ni, Zn) and s-process (Y) elements. We found that NGC 3201 is a homogeneous, mono-metallic ([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, 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).

References in corpus (61)

• The chemical composition of the Sun
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• Neutron capture in low mass Asymptotic Giant Branch stars: cross sections and abundance signatures
• Elemental Abundance Survey of The Galactic Thick Disk
• Intrinsic iron spread and a new metallicity scale for Globular Clusters
• Abundances for Globular Cluster Giants: I. Homogeneous Metallicities for 24 Clusters
• Na-O Anticorrelation and HB. VIII. Proton-capture elements and metallicities in 17 globular clusters from UVES spectra
• The ASAS-SN Catalog of Variable Stars I: The Serendipitous Survey
• Evolution, nucleosynthesis and yields of low mass AGB stars at different metallicities (II): the FRUITY database
• The Rise of the s-Process in the Galaxy
• Evolution, nucleosynthesis and yields of AGB stars at different metallicities (III): intermediate mass models, revised low mass models and the ph-FRUITY interface
• A Globular Cluster Metallicity Scale Based on the Abundance of Fe II
• A Comparison of Elemental Abundance Ratios in Globular Clusters, Field Stars, and Dwarf Spheroidal Galaxies
• Probing the Outer Galactic halo with RR Lyrae from the Catalina Surveys
• On a new theoretical framework for RR Lyrae stars I: the metallicity dependence
• Improved Laboratory Transition Probabilities for Neutral Chromium and Re-determination of the Chromium Abundance for the Sun and Three Stars
• Deciphering the 3D structure of the old Galactic bulge from the OGLE RR Lyrae stars
• A pulsational approach to near infrared and visual magnitudes of RR Lyrae stars
• The SEGUE Stellar Parameter Pipeline. V. Estimation of Alpha-Element Abundance Ratios From Low-Resolution SDSS/SEGUE Stellar Spectra
• Stellar Archaeology -- Exploring the Universe with Metal-Poor Stars
• Improved Ti II log(gf) Values and Abundance Determinations in the Photospheres of the Metal-Poor Star HD 84937
• Ruprecht 106: the first single population Globular Cluster?
• The composition of HB stars : RR Lyrae variables
• First Kepler results on RR Lyrae stars
• Fe I Oscillator Strengths for the Gaia-ESO Survey
• Discovery of $\sim$ 9,000 new RR Lyrae in the Southern Catalina Surveys
• The Konkoly Blazhko Survey: Is light-curve modulation a common property of RRab stars?
• Improved Ni I log(gf) Values and Abundance Determinations in the Photospheres of the Sun and Metal-poor Star HD 84937
• Optical and Near-Infrared UBVRIJHK Photometry for the RR Lyrae stars in the Nearby Globular Cluster M4 (NGC 6121)
• On the Blazhko Effect in RR Lyrae Stars
• On the distance of the globular cluster M4 (NGC 6121) using RR Lyrae stars: I. optical and near-infrared Period-Luminosity and Period-Wesenheit relations
• The Chemical Compositions of Variable Field Horizontal Branch Stars: RR Lyrae Stars
• Fe I Oscillator Strengths for Transitions from High-lying Even-Parity Levels
• Weak Galactic halo--dwarf spheroidal connection from RR Lyrae stars
• MIKiS: the Multi-Instrument Kinematic Survey of Galactic Globular Clusters. I. Velocity dispersion profiles and rotation signals of 11 globular clusters
• The Dwarf Spheroidal Companions to M31: Variable Stars in Andromeda VI
• Calcium and light-elements abundance variations from high resolution spectroscopy in globular clusters
• Spectroscopic Comparison of Metal-Rich RRab Stars of the Galactic Field with Their Metal-Poor Counterparts
• Long time-scale behavior of the Blazhko effect from rectified Kepler data
• Variable stars in Local Group Galaxies - II. Sculptor dSph
• On a new theoretical framework for RR Lyrae stars II: Mid--Infrared Period--Luminosity--Metallicity Relations
• The Chemical Compositions of Non-Variable Red and Blue Field Horizontal Branch Stars
• First stars XIII. Two extremely metal-poor RR Lyrae stars?
• RR Lyrae stars in Galactic globular clusters. VI. The Period-Amplitude relation
• The origin of the spurious iron spread in the globular cluster NGC 3201
• Chemical abundances of solar neighborhood RR Lyrae stars
• Template RR Lyrae H alpha, H beta, and H gamma Velocity Curves
• The RRC Stars: Chemical Abundances and Envelope Kinematics
• An In-Depth Spectroscopic Analysis of the Blazhko Star RR Lyr. I. Characterisation of the star: abundance analysis and fundamental parameters
• The Origin and Chemical Evolution of the Exotic Globular Cluster NGC3201
• The chemical composition of the low-mass Galactic globular cluster NGC 6362
• Probing the early chemical evolution of the Sculptor dSph with purely old stellar tracers
• Fe I oscillator strengths for transitions from high-lying odd-parity levels
• On the RR Lyrae stars in globulars: V. the complete Near-Infrared (JHKs) census of omega Centauri RR Lyrae variables
• The QUEST RR Lyrae Survey: III. The Low Galactic Latitude Catalogue
• RR Lyrae Variables in the Globular Clusters of M31: a First Detection of Likely Candidates
• Ancient stars beyond the Local Group: RR Lyrae variables and Blue Horizontal Branch stars in Sculptor Group Dwarf Galaxies
• Variable Stars in the Cetus dSph Galaxy: Population Gradients and Connections with the Star Formation History
• The Carina Project. VI. The helium burning variable stars
• The STREGA survey. II. Globular Cluster Palomar 12
• A Photometric Study of the Outer Halo Globular Cluster NGC 5824

Cited by in corpus (21)

• Chemo-kinematics of the $Gaia$ RR Lyrae: the halo and the disc
• Selecting accreted populations: metallicity, elemental abundances, and ages of the Gaia-Sausage-Enceladus and Sequoia populations
• On the use of field RR Lyrae as Galactic probes: I. The Oosterhoff dichotomy based on fundamental variables
• On the Use of Field RR Lyrae as Galactic Probes. II. A new $\Delta$S calibration to estimate their metallicity
• High-precision distance measurements with classical pulsating stars
• Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves: I. Period-Fourier-Metallicity Relations for Fundamental Mode RR Lyrae
• Local RR Lyrae Stars: native and alien
• On a new method to estimate distance, reddening and metallicity of RR Lyrae stars using optical/near-infrared ($B$,$V$,$I$,$J$,$H$,$K$) mean magnitudes: $\omega$ Centauri as a first test case
• Evolutionary and pulsation properties of Type II Cepheids
• A new and homogeneous metallicity scale for Galactic classical Cepheids II. The abundance of iron and alpha elements
• Chemical Compositions of Field and Globular Cluster RR~Lyrae Stars: II. omega Centauri
• A chemo-dynamical link between the Gjöll stream and NGC 3201
• On the Use of Field RR Lyrae as Galactic Probes. V. Optical and radial velocity curve templates
• Excess of Ca (and Sc) produced in globular cluster multiple populations: a first census in 77 Galactic globular clusters
• The GALAH survey: Tracing the Milky Way's formation and evolution through RR Lyrae stars
• A theoretical scenario for Galactic RR Lyrae in the Gaia database: constraints on the parallax offset
• RR Lyrae stars as probes of the outer Galactic halo: Chemical and kinematic analysis of a pilot sample
• NLTE CNO abundances in a sample of nine field RR lyr type stars
• On the photometric metallicity of Oosterhoff-type I and II RRab stars
• Bright single-mode RR Lyrae stars: matching Gaia EDR3 with pulsation and evolutionary models
• On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid