New period-luminosity and period-color relations of classical Cepheids. IV. The low-metallicity galaxies IC 1613, WLM, Pegasus, Sextans A and B, and Leo A in comparison to SMC

TL;DR

This study compares period-luminosity and period-color relations of Cepheids in low-metallicity dwarf galaxies, revealing their similarity to SMC Cepheids and differences from LMC, enabling precise distance measurements.

Contribution

It establishes new period-luminosity and period-color relations for Cepheids in several low-metallicity dwarf galaxies, improving distance estimation accuracy.

Findings

Cepheids in the studied dwarf galaxies have similar P-C and P-L relations to SMC Cepheids.

Relations differ significantly from those in LMC and the solar neighborhood.

Reliable distance moduli for the dwarf galaxies are derived using these relations.

Abstract

The metal-poor, fundamental-mode (P0) and first-overtone (P1) Cepheids in the dwarf galaxies IC 1613, WLM, Pegasus, Sextans A, Sextans B, and Leo A are compared with the about equally metal-poor Cepheids of the Small Magellanic Cloud (SMC). The period-color (P-C) and period-luminosity (P-L) relations of the seven galaxies are indistinguishable, but differ distinctly from those in the Large Magellanic Cloud (LMC) and the solar neighborhood. Adopting (m-M)^{0}_{SMC}=18.93 from independent evidence, one can determine reliable distance moduli for the other dwarf galaxies of (m-M)^{0} = 24.34+/-0.03, 24.95+/-0.03, 24.87+/-0.06, 25.60+/-0.03 (mean for Sextans A & B), and 24.59+/-0.03, respectively.