Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

On the Use of Field RR Lyrae As Galactic Probes: IV. New Insights Into and Around the Oosterhoff Dichotomy

Journal Article · · The Astrophysical Journal
 [1];  [1];  [2];  [3];  [4];  [4];  [4];  [5];  [6];  [7];  [1];  [8];  [9];  [1];  [10];  [8];  [10];  [10];  [11];  [12] more »;  [1];  [1];  [13];  [14];  [15];  [12];  [16];  [17];  [10];  [18];  [19];  [20];  [21] « less
  1. Istituto Nazionale di Astrofisica (INAF), Roma (Italy); Agenzia Spaziale Italiana (ASI), Roma (Italy)
  2. Università di Roma Tor Vergata (Italy); Istituto Nazionale di Astrofisica (INAF), Roma (Italy); Universidade Federal do Rio Grande do Sul, Porto Alegre (Brazil)
  3. Università di Roma Tor Vergata (Italy); Istituto Nazionale di Astrofisica (INAF), Roma (Italy)
  4. Istituto Nazionale di Astrofisica (INAF), Roma (Italy)
  5. Carnegie Institute of Science, Pasadena, CA (United States)
  6. University of Texas, Austin, TX (United States)
  7. Université de Nice Sophia-Antipolis (France)
  8. Dartmouth College, Hanover, NH (United States)
  9. Istituto Nazionale di Astrofisica (INAF), Napoli (Italy)
  10. Universität Heidelberg (Germany)
  11. Universitá di Bologna (Italy)
  12. Iowa State University, Ames, IA (United States)
  13. Cerro Tololo Inter-American Observatory (CTIO), La Serena (Chile)
  14. University of Tokyo (Japan)
  15. Instituto de Astrofísica de Canarias (IAC), La Laguna (Spain)
  16. Florida Atlantic University, Boca Raton, FL (United States)
  17. Istituto Nazionale di Astrofisica (INAF), Trieste (Italy)
  18. Liverpool John Moores University (United Kingdom)
  19. National Research Council, Victoria (Canada)
  20. European Southern Observatory (ESO), Munchen (Germany); Excellence Cluster ORIGINS, Munchen (Germany)
  21. Pontificia Universidad Catolica de Chile, Santiago (Chile)
+ Show Author Affiliations
We discuss the largest and most homogeneous spectroscopic data set of field RR Lyrae variables (RRLs) available to date. We estimated abundances using both high-resolution and low-resolution ($$Δ$$S method) spectra for fundamental (RRab) and first overtone (RRc) RRLs. The iron abundances for 7941 RRLs were supplemented with similar estimates that are available in the literature, ending up with 9015 RRLs (6150 RRab, 2865 RRc). The metallicity distribution shows a mean value of $$\langle$$[Fe/H]$$\rangle$$ = -1.51 ± 0.01, and $$σ$$(standard deviation) = 0.41 dex with a long metal-poor tail approaching [Fe/H] ≃ - 3 and a sharp metal-rich tail approaching solar iron abundance. The RRab variables are more metal-rich ( $$\langle$$[Fe/H]$$\rangle$$ ab = -1.48 ± 0.01, $$σ$$ = 0.41 dex) than RRc variables ($$\langle$$[Fe/H]$$\rangle$$ c = -1.58 ± 0.01, $$σ$$ = 0.40 dex). The relative fraction of RRab variables in the Bailey diagram (visual amplitude versus period) located along the short-period (more metal-rich) and the long-period (more metalpoor) sequences are 80% and 20%, while RRc variables display an opposite trend, namely 30% and 70%, respectively. We found that the pulsation period of both RRab and RRc variables steadily decreases when moving from the metal-poor to the metal-rich regime. Furthermore, the visual amplitude shows the same trend, but RRc amplitudes are almost two times more sensitive than RRab amplitudes to metallicity. We also investigated the dependence of the population ratio (N$$c$$/Ntot) of field RRLs on the metallicity and we found that the distribution is more complex than in globular clusters. The population ratio steadily increases from ~0.25 to ~0.36 in the metal-poor regime, it decreases from ~0.36 to ~0.18 for -1.8 ≤ [Fe/H] ≤ -0.9 and it increases to a value of ~0.3 approaching solar iron abundance.
Research Organization:
US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS)
Sponsoring Organization:
USDOE; National Aeronautics and Space Administration (NASA); National Science Foundation (NSF)
OSTI ID:
1983176
Alternate ID(s):
OSTI ID: 23158837
Journal Information:
The Astrophysical Journal, Journal Name: The Astrophysical Journal Journal Issue: 2 Vol. 919; ISSN 0004-637X
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English

References (75)

Horizontal branch stars: the interplay between observations and theory, and insights into the formation of the Galaxy journal February 2009
A comprehensive view of the Virgo stellar stream journal June 2014
Atmospheric dynamics in RR Lyrae stars journal May 2013
Gaia Data Release 2 : Specific characterisation and validation of all-sky Cepheids and RR Lyrae stars★ journal January 2019
Dynamical structure of the pulsating atmosphere of RR Lyrae journal March 2019
Horizontal branch morphology: A new photometric parametrization journal September 2019
Purveyors of fine halos journal May 2020
RR Lyrae variables in Galactic globular clusters journal October 2004
Color-magnitude diagrams for seven globular clusters. journal October 1955
Globular cluster orbits and second parameter effects journal March 1993
The metallicities and kinematics of RR Lyrae variables, 1: New observations of local stars journal September 1994
The Topology of the RR Lyrae Instability Strip and the Oosterhoff Dichotomy journal November 1995
A Catalog of Parameters for Globular Clusters in the Milky Way journal October 1996
A Spectroscopic Study of the RR Lyrae Stars. journal July 1959
Color-Magnitude Diagram for Disk Clobular Cluster NGC 6356 Compared with Halo Clusters. journal May 1960
On the Difference Between the Oosterhoff Types i and II Globular Clusters journal September 1971
The Oosterhoff period groups and the age of globular clusters. II - Properties of RR Lyrae stars in six clusters - The P-L-A relation journal August 1981
The horizontal-branch stars in globular clusters. I - The period-shift effect, the luminosity of the horizontal branch, and the age-metallicity relation journal February 1990
Detection of a galactic color gradient for blue horizontal-branch stars of the halo field and implications for the halo age and density distributions journal July 1991
The horizontal-branch stars in globular clusters. 2: The second parameter phenomenon journal March 1994
Pulsation and stability of RR Lyrae stars. 1: Instability strip journal July 1994
The Chemical Composition of Field RR Lyrae Stars. I. Iron and Calcium journal March 1996
RR Lyrae Luminosity Differences between Oosterhoff Group I and II Cluster Systems and the Origin of the Oosterhoff Dichotomy journal September 1999
Maps of Dust Infrared Emission for Use in Estimation of Reddening and Cosmic Microwave Background Radiation Foregrounds journal June 1998
Variable Stars in Galactic Globular Clusters journal November 2001
Variable Stars in the Unusual, Metal-rich Globular Cluster NGC 6388 journal August 2002
Hubble Space TelescopeSnapshot Study of Variable Stars in Globular Clusters: The Inner Region of NGC 6441 journal September 2003
The Radial Velocity Experiment (RAVE): First Data Release journal September 2006
Variable Stars in Metal-Rich Globular Clusters. III. NGC 6539 journal December 2006
The Segue Stellar Parameter Pipeline. i. Description and Comparison of Individual Methods journal October 2008
SEGUE: A SPECTROSCOPIC SURVEY OF 240,000 STARS WITH g = 14-20 journal April 2009
An Oosterhoff Analysis of the Galactic Bulge Field rr Lyrae Stars: Implications on Their Absolute Magnitudes journal September 2009
AMPLITUDE FINE STRUCTURE IN THE CEPHEIDP-LRELATION. I. AMPLITUDE DISTRIBUTION ACROSS THE RR LYRAE INSTABILITY STRIP MAPPED USING THE ACCESSIBILITY RESTRICTION IMPOSED BY THE HORIZONTAL BRANCH journal September 2010
Measuring Reddening with Sloan Digital sky Survey Stellar Spectra and Recalibrating sfd journal August 2011
Neowise Observations of Near-Earth Objects: Preliminary Results journal December 2011
Metal Abundances, Radial Velocities, and Other Physical Characteristics for the rr Lyrae Stars in the Kepler Field journal August 2013
TRACING THE ORPHAN STREAM TO 55 kpc WITH RR LYRAE STARS journal September 2013
The Chemical Compositions of rr Lyrae type c Variable Stars journal January 2014
On a new Theoretical Framework for rr Lyrae Stars. i. the Metallicity Dependence journal July 2015
The Carina Project. ix. on Hydrogen and Helium Burning Variables journal November 2015
The Chemical Compositions of Variable Field Horizontal-Branch Stars: rr Lyrae Stars journal November 2011
Long-Timescale Behavior of the Blazhko Effect from Rectified Kepler data journal July 2014
The Eleventh and Twelfth data Releases of the Sloan Digital sky Survey: Final data from Sdss-Iii journal July 2015
The Relationship of Sodium and Oxygen in Galactic Field RR Lyrae Stars journal December 2017
LAMOST spectral survey — An overview journal June 2012
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) journal August 2012
Abundances of 23 field RR Lyrae stars journal October 2013
Weak Galactic Halo-Dwarf Spheroidal Connection from rr Lyrae Stars journal December 2014
Spectroscopic and photometric time series of the bright RRc star T Sex journal November 2020
The mass fraction of halo stars contributed by the disruption of globular clusters in the E-MOSAICS simulations journal February 2020
Blazhko effect in the Galactic bulge fundamental mode RR Lyrae stars – II. Modulation shapes, amplitudes, and periods journal March 2020
Unveiling short-period binaries in the inner VVV bulge journal April 2021
RR Lyrae variables: visual and infrared luminosities, intrinsic colours and kinematics journal September 2013
Chemical abundances of solar neighbourhood RR Lyrae stars★ journal January 2015
Blazhko effect in the Galactic bulge fundamental mode RR Lyrae stars – I. Incidence rate and differences between modulated and non-modulated stars journal January 2017
Blazhko Effect in the first overtone RR Lyrae stars of the OGLE Galactic bulge collection journal July 2018
On the Oosterhoff dichotomy in the Galactic bulge: I. spatial distribution journal January 2019
Local RR Lyrae stars: native and alien journal December 2019
On the use of Gaia magnitudes and new tables of bolometric corrections journal June 2018
Long-term photometric monitoring of Messier 5 variables - II. Blazhko stars journal January 2011
on the rr Lyrae Stars in Globulars. iv. ω Centauri Optical Ubvri Photometry journal November 2016
Machine-learned Identification of RR Lyrae Stars from Sparse, Multi-band Data: The PS1 Sample journal May 2017
On the RR Lyrae Stars in Globulars. V. The Complete Near-infrared ( JHK s ) Census of ω Centauri RR Lyrae Variables journal March 2018
Identification of RR Lyrae Stars in Multiband, Sparsely Sampled Data from the Dark Energy Survey Using Template Fitting and Random Forest Classification journal June 2019
Spectroscopic Comparison of Metal-rich RRab Stars of the Galactic Field with their Metal-poor Counterparts journal January 2017
The RRc Stars: Chemical Abundances and Envelope Kinematics journal October 2017
On a New Method to Estimate the Distance, Reddening, and Metallicity of RR Lyrae Stars Using Optical/Near-infrared ( B, V, I, J, H, K ) Mean Magnitudes: ω Centauri as a First Test Case journal January 2019
Chemical Compositions of Field and Globular Cluster RR Lyrae Stars. II. ω Centauri∗ journal August 2019
On the Use of Field RR Lyrae as Galactic Probes. I. The Oosterhoff Dichotomy Based on Fundamental Variables journal September 2019
On the Use of Field RR Lyrae as Galactic Probes. II. A New ΔS Calibration to Estimate Their Metallicity* journal February 2021
Possible Evidence of Hydrogen Emission in the First-overtone and Multimode RR Lyrae Variables journal March 2021
On the Use of Field RR Lyrae as Galactic Probes. III. The α-element Abundances* journal June 2021
Probing the Galactic Halo with RR Lyrae Stars. I. The Catalog journal April 2020
On the Impact of Helium Content on the RR Lyrae Distance Scale journal August 2018
On the Metamorphosis of the Bailey Diagram for RR Lyrae Stars journal June 2020

Similar Records

Metallicity of Galactic RR Lyrae from Optical and Infrared Light Curves. II. Period–Fourier–Metallicity Relations for First Overtone RR Lyrae
Journal Article · Thu Jun 02 00:00:00 EDT 2022 · The Astrophysical Journal · OSTI ID:1983259
RR LYRAE VARIABLES IN M33. II. OOSTERHOFF PROPERTIES AND RADIAL TRENDS
Journal Article · Fri Nov 19 23:00:00 EST 2010 · Astrophysical Journal · OSTI ID:21471166
METAL ABUNDANCES, RADIAL VELOCITIES, AND OTHER PHYSICAL CHARACTERISTICS FOR THE RR LYRAE STARS IN THE KEPLER FIELD
Journal Article · Tue Aug 20 00:00:00 EDT 2013 · Astrophysical Journal · OSTI ID:22130951

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
Astronomy & Astrophysics
Milky Way stellar halo
RR Lyrae variable stars
Spectroscopy