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Title: On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations

Abstract

We present new theoretical period–luminosity–metallicity (PLZ) relations for RR Lyræ stars (RRLs) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad range of metal abundances ( Z = 0.0001–0.0198). In deriving the light curves, we tested two sets of atmospheric models and found no significant difference between the resulting mean magnitudes. We also compare our theoretical relations to empirical relations derived from RRLs in both the field and in the globular cluster M4. Our theoretical PLZ relations were combined with multi-wavelength observations to simultaneously fit the distance modulus, μ {sub 0}, and extinction, A {sub V}, of both the individual Galactic RRL and of the cluster M4. The results for the Galactic RRL are consistent with trigonometric parallax measurements from Gaia ’ s first data release. For M4, we find a distance modulus of μ {sub 0} = 11.257 ± 0.035 mag with A {sub V}= 1.45 ± 0.12 mag, which is consistent with measurements from other distance indicators. This analysis has shown that, when considering a sample covering a range of iron abundances, the metallicity spread introduces a dispersion in the PL relation on the order of 0.13 mag.more » However, if this metallicity component is accounted for in a PLZ relation, the dispersion is reduced to ∼0.02 mag at mid-infrared wavelengths.« less

Authors:
; ;  [1]; ; ;  [2]; ;  [3]; ;  [4]; ; ;  [5];  [6];  [7];  [8];  [9]
  1. Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States)
  2. Department of Physics, Università di Roma Tor Vergara, via della Ricerca Scientifica 1, I-00133 Roma (Italy)
  3. INAF-Osservatorio Astronomico di Capodimonte, Salita Moiarello 16, I-80131 Napoli (Italy)
  4. Dipartimento di Fisica, Università di Pisa, Lago Bruno Pontecorvo 3, I-56127, Pisa (Italy)
  5. Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
  6. Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)
  7. Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)
  8. Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom)
  9. NRC-Herzberg, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria BC V9E 2E7 (Canada)
Publication Date:
OSTI Identifier:
22663564
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 841; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; COMPARATIVE EVALUATIONS; DISPERSIONS; DISTANCE; INDICATORS; IRON; LUMINOSITY; METALLICITY; NONLINEAR PROBLEMS; STARS; TIME DEPENDENCE; VISIBLE RADIATION; WAVELENGTHS

Citation Formats

Neeley, Jillian R., Marengo, Massimo, Trueba, Nicolas, Bono, Giuseppe, Braga, Vittorio F., Magurno, Davide, Dall’Ora, Massimo, Marconi, Marcella, Tognelli, Emanuele, Moroni, Pier G. Prada, Beaton, Rachael L., Madore, Barry F., Seibert, Mark, Freedman, Wendy L., Monson, Andrew J., Scowcroft, Victoria, and Stetson, Peter B., E-mail: jrneeley@iastate.edu. On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA713D.
Neeley, Jillian R., Marengo, Massimo, Trueba, Nicolas, Bono, Giuseppe, Braga, Vittorio F., Magurno, Davide, Dall’Ora, Massimo, Marconi, Marcella, Tognelli, Emanuele, Moroni, Pier G. Prada, Beaton, Rachael L., Madore, Barry F., Seibert, Mark, Freedman, Wendy L., Monson, Andrew J., Scowcroft, Victoria, & Stetson, Peter B., E-mail: jrneeley@iastate.edu. On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations. United States. doi:10.3847/1538-4357/AA713D.
Neeley, Jillian R., Marengo, Massimo, Trueba, Nicolas, Bono, Giuseppe, Braga, Vittorio F., Magurno, Davide, Dall’Ora, Massimo, Marconi, Marcella, Tognelli, Emanuele, Moroni, Pier G. Prada, Beaton, Rachael L., Madore, Barry F., Seibert, Mark, Freedman, Wendy L., Monson, Andrew J., Scowcroft, Victoria, and Stetson, Peter B., E-mail: jrneeley@iastate.edu. Thu . "On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations". United States. doi:10.3847/1538-4357/AA713D.
@article{osti_22663564,
title = {On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations},
author = {Neeley, Jillian R. and Marengo, Massimo and Trueba, Nicolas and Bono, Giuseppe and Braga, Vittorio F. and Magurno, Davide and Dall’Ora, Massimo and Marconi, Marcella and Tognelli, Emanuele and Moroni, Pier G. Prada and Beaton, Rachael L. and Madore, Barry F. and Seibert, Mark and Freedman, Wendy L. and Monson, Andrew J. and Scowcroft, Victoria and Stetson, Peter B., E-mail: jrneeley@iastate.edu},
abstractNote = {We present new theoretical period–luminosity–metallicity (PLZ) relations for RR Lyræ stars (RRLs) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad range of metal abundances ( Z = 0.0001–0.0198). In deriving the light curves, we tested two sets of atmospheric models and found no significant difference between the resulting mean magnitudes. We also compare our theoretical relations to empirical relations derived from RRLs in both the field and in the globular cluster M4. Our theoretical PLZ relations were combined with multi-wavelength observations to simultaneously fit the distance modulus, μ {sub 0}, and extinction, A {sub V}, of both the individual Galactic RRL and of the cluster M4. The results for the Galactic RRL are consistent with trigonometric parallax measurements from Gaia ’ s first data release. For M4, we find a distance modulus of μ {sub 0} = 11.257 ± 0.035 mag with A {sub V}= 1.45 ± 0.12 mag, which is consistent with measurements from other distance indicators. This analysis has shown that, when considering a sample covering a range of iron abundances, the metallicity spread introduces a dispersion in the PL relation on the order of 0.13 mag. However, if this metallicity component is accounted for in a PLZ relation, the dispersion is reduced to ∼0.02 mag at mid-infrared wavelengths.},
doi = {10.3847/1538-4357/AA713D},
journal = {Astrophysical Journal},
number = 2,
volume = 841,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}