Metal Rich RR Lyrae Variables: II. The Pulsational Scenario

Abstract

We present a theoretical investigation on the pulsational behavior of metal-rich RR Lyrae variables over the range of evolutionary parameters suitable for stars with metallicities Z= 0.006, 0.01 and 0.02. With the addition of similar results for metal-poor pulsators we discuss the theoretical pulsational scenario covering the metallicity range from Z=0.0001 to 0.02. We find that the distribution of field ab-type RR Lyrae stars in the period-metallicity plane can be easily understood within the framework of the present theoretical scenario, suggesting that the Oosterhoff dichotomy also affects field variables. Theoretical predictions concerning the amplitude-period diagram are discussed and compared with observational data. We find a general agreement for metal-poor ([Fe/H]<-1.4) RR Lyrae stars, whereas more metal-rich variables show amplitudes smaller than those predicted for pulsators originated from old, low-mass evolving stars. Alternatively, the agreement between theory and observations would require that a substantial fraction of metal-rich RR Lyrae variables in the Galactic field were younger than approximately 2 Gyr. The comparison between the pulsational behavior of RR Lyrae either in the Galactic field or in the Galactic bulge discloses the evidence that, at least as far as RR Lyrae variables are concerned, the metal-rich components of the bulge and of the field population appear quite similar.

21 pages, 19 ps figures, 5 ps tables, uses aaspp4.sty and tighten.sty, accepted for publication in ApJ

References in corpus (5)

• The MACHO Project LMC Variable Star Inventory: I. Beat Cepheids - Conclusive Evidence for the Excitation of the Second Overtone in Classical Cepheids
• Nonlinear Investigation of the Pulsational Properties of RR Lyrae Variables
• Metal Rich RR Lyrae Variables: I. The Evolutionary Scenario
• Metallicity Effects on RR Lyrae Variables
• CCD PHOTOMETRY OF RR LYRAE STARS IN M5 AS A TEST FOR THE PULSATIONAL SCENARIO

Cited by in corpus (57)

• Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
• On a new theoretical framework for RR Lyrae stars I: the metallicity dependence
• Deciphering the 3D structure of the old Galactic bulge from the OGLE RR Lyrae stars
• Intermediate-mass star models with different helium and metal contents
• Metal Abundances, Radial Velocities and other Physical Characteristics for the RR Lyrae Stars in the Kepler Field
• RR-Lyrae-type pulsations from a 0.26-solar-mass star in a binary system
• Chemo-kinematics of the $Gaia$ RR Lyrae: the halo and the disc
• The Initial Helium Abundance of the Galactic Globular Cluster System
• Optical and Near-Infrared UBVRIJHK Photometry for the RR Lyrae stars in the Nearby Globular Cluster M4 (NGC 6121)
• The Variable Stars and Blue Horizontal Branch of the Metal-Rich Globular Cluster NGC 6441
• RR Lyrae stars in Galactic globular clusters. II. A theoretical approach to variables in M3
• Fourier analysis of non-Blazhko ab-type RR Lyrae stars observed with the Kepler space telescope
• Pulsational M_V versus [Fe/H] relation(s) for globular cluster RR Lyrae variables
• Theoretical models for Bump Cepheids
• CCD Photometry of Galactic Globular Clusters. IV. The NGC 1851 RR Lyraes
• Variable Stars in the Unusual, Metal-Rich Globular Cluster NGC 6441
• CU Comae: a new field double-mode RR Lyrae, the most metal poor discovered to date
• Spectroscopic Comparison of Metal-Rich RRab Stars of the Galactic Field with Their Metal-Poor Counterparts
• On the RR Lyrae stars in globulars: IV. $\omega$ Centauri Optical UBVRI Photometry
• Variable stars in Local Group Galaxies - II. Sculptor dSph
• BVI time series data of the Galactic Globular Cluster NGC3201. I. RR Lyrae stars
• The Metallicity Dependence of the Fourier Components of RR Lyrae Light Curves is the Oosterhoff/Arp/Preston Period Ratio Effect in Disguise
• Variable stars in the ultra-faint dwarf spheroidal galaxy Ursa Major I
• RR Lyrae stars in Galactic globular clusters. VI. The Period-Amplitude relation
• The occurrence of Binary Evolution Pulsators in the classical instability strip of RR Lyrae and Cepheid variables
• The ACS LCID Project: RR Lyrae stars as tracers of old population gradients in the isolated dwarf spheroidal galaxy Tucana
• On the Predicted and Observed Color Boundaries of the RR Lyrae Instability Strip as a Function of Metallicity
• Near-Infrared Observations of RR Lyrae variables in Galactic Globular Clusters: I. The case of M92
• RR Lyrae From Binary Evolution: Abundant, Young and Metal-Rich
• On the distance of the globular cluster M4 (NGC 6121) using RR Lyrae stars: II. Mid-infrared period-luminosity relations
• Metallicities for Double Mode RR Lyrae in the Large Magellanic Cloud
• The ISLAnds Project III: Variable Stars in Six Andromeda Dwarf Spheroidal Galaxies
• Evolutionary and pulsation properties of Type II Cepheids
• A DECam View of the Diffuse Dwarf Galaxy Crater II: Variable Stars
• New Near-Infrared $JH{K}_s$ light-curve templates for RR Lyrae variables
• RR Lyrae variables in M5 as a test of pulsational theory
• On the separation between RR Lyrae and Type II Cepheids and their importance for distance determination: the case of $\omega$ Cen
• Radial Stellar Pulsation and 3D Convection. I. Numerical Methods and Adiabatic Test Cases
• Period Change Similarities among the RR Lyrae Variables in Oosterhoff I and Oosterhoff II Globular Systems
• Gauging the Helium Abundance of the Galactic Bulge RR Lyrae Stars
• The Carina Project. VI. The helium burning variable stars
• Radial Stellar Pulsation and Three-Dimensional Convection. II. Two-Dimensional Convection In Full Amplitude Radial Pulsation
• On the Use of Field RR Lyrae as Galactic Probes. V. Optical and radial velocity curve templates
• The GALAH survey: Tracing the Milky Way's formation and evolution through RR Lyrae stars
• Homogeneous Photometry VI: Variable Stars in the Leo I Dwarf Spheroidal Galaxy
• Near-infrared Census of RR Lyrae variables in the Messier 3 globular cluster and the Period--Luminosity Relations
• On the Use of Field RR Lyrae as Galactic Probes. VI. Mixed mode RR Lyrae variables in Fornax and in nearby dwarf galaxies
• Radial Stellar Pulsation and Three-Dimensional Convection. IV. Full Amplitude Three-Dimensional Solutions
• Amplitude Fine-Structure in the Cepheid P-L Relation I: Amplitude Distribution Across the RR Lyrae Instability Strip Mapped Using the Accessibility Restriction Imposed by the Horizontal Branch
• On the primordial helium content: CMB and stellar constraints
• Radial Stellar Pulsation and Three-Dimensional Convection. III. Comparison of Two-Dimensional and Three-Dimensional Convection Effects on Radial Pulsation
• RR Lyrae Stars in Intermediate-age Magellanic Clusters: Membership Probabilities and Delay Time Distribution
• Analysis of a selected sample of RR Lyrae stars in LMC from OGLE III
• On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid
• First direct detection of an RR Lyrae star conclusively associated with an intermediate-age cluster
• New theoretical predictions on Type II Cepheids: towards a self consistent Pop. II distance scale
• A Multiband Photometric Study of RR Lyrae Stars in M53 (NGC 5024)