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Title: A Method for Improving Galactic Cepheid Reddenings and Distances

Abstract

We present a new photometric method by which improved high-precision reddenings and true distance moduli can be determined to individual Galactic Cepheids once distance measurements are available. We illustrate that the relative positioning of stars in the Cepheid period–luminosity (PL) relation (Leavitt law) is preserved as a function of wavelength. This information then provides a powerful constraint for determining reddenings to individual Cepheids, as well as their distances. As a first step, we apply this method to the 59 Cepheids in the compilation of Fouqué et al. Updated reddenings, distance moduli (or parallaxes), and absolute magnitudes in seven (optical through near-infrared) bands are given. From these intrinsic quantities, multiwavelength PL and color–color relations are derived. We find that the V -band period–luminosity–color relation has an rms scatter of only 0.06 mag, so that individual Cepheid distances can be measured to 3%, compared with dispersions of 6 to 13% for the one-parameter K through B PL relations, respectively. This method will be especially useful in conjunction with the new accurate parallax sample upcoming from Gaia .

Authors:
 [1]; ;  [2]
  1. The Observatories Carnegie Institution for Science 813 Santa Barbara St., Pasadena, CA 91101 (United States)
  2. Dept. of Astronomy and Astrophysics, University of Chicago, Chicago, IL (United States)
Publication Date:
OSTI Identifier:
22663515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 842; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; CEPHEIDS; COMPARATIVE EVALUATIONS; DISPERSIONS; GALAXIES; LIMITING VALUES; LUMINOSITY; PHOTOMETRY; POSITIONING; WAVELENGTHS

Citation Formats

Madore, Barry F., Freedman, Wendy L., and Moak, Sandy, E-mail: barry.f.madore@gmail.com, E-mail: sandymoak@gmail.com, E-mail: wfreedman@uchicago.edu. A Method for Improving Galactic Cepheid Reddenings and Distances. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA6E4D.
Madore, Barry F., Freedman, Wendy L., & Moak, Sandy, E-mail: barry.f.madore@gmail.com, E-mail: sandymoak@gmail.com, E-mail: wfreedman@uchicago.edu. A Method for Improving Galactic Cepheid Reddenings and Distances. United States. doi:10.3847/1538-4357/AA6E4D.
Madore, Barry F., Freedman, Wendy L., and Moak, Sandy, E-mail: barry.f.madore@gmail.com, E-mail: sandymoak@gmail.com, E-mail: wfreedman@uchicago.edu. Sat . "A Method for Improving Galactic Cepheid Reddenings and Distances". United States. doi:10.3847/1538-4357/AA6E4D.
@article{osti_22663515,
title = {A Method for Improving Galactic Cepheid Reddenings and Distances},
author = {Madore, Barry F. and Freedman, Wendy L. and Moak, Sandy, E-mail: barry.f.madore@gmail.com, E-mail: sandymoak@gmail.com, E-mail: wfreedman@uchicago.edu},
abstractNote = {We present a new photometric method by which improved high-precision reddenings and true distance moduli can be determined to individual Galactic Cepheids once distance measurements are available. We illustrate that the relative positioning of stars in the Cepheid period–luminosity (PL) relation (Leavitt law) is preserved as a function of wavelength. This information then provides a powerful constraint for determining reddenings to individual Cepheids, as well as their distances. As a first step, we apply this method to the 59 Cepheids in the compilation of Fouqué et al. Updated reddenings, distance moduli (or parallaxes), and absolute magnitudes in seven (optical through near-infrared) bands are given. From these intrinsic quantities, multiwavelength PL and color–color relations are derived. We find that the V -band period–luminosity–color relation has an rms scatter of only 0.06 mag, so that individual Cepheid distances can be measured to 3%, compared with dispersions of 6 to 13% for the one-parameter K through B PL relations, respectively. This method will be especially useful in conjunction with the new accurate parallax sample upcoming from Gaia .},
doi = {10.3847/1538-4357/AA6E4D},
journal = {Astrophysical Journal},
number = 1,
volume = 842,
place = {United States},
year = {Sat Jun 10 00:00:00 EDT 2017},
month = {Sat Jun 10 00:00:00 EDT 2017}
}