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Title: Period–luminosity relations derived from the OGLE-III fundamental mode Cepheids. II. The small magellanic cloud Cepheids

Journal Article · · Astrophysical Journal
 [1];  [2]; ;  [3]
  1. Graduate Institute of Astronomy, National Central University, Jhongli 32001, Taiwan (China)
  2. Department of Physics, SUNY Oswego, Oswego, NY 13126 (United States)
  3. Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

In this paper we present multi-band period–luminosity (P–L) relations for fundamental mode Cepheids in the SMC. The optical VI-band mean magnitudes for these SMC Cepheids were taken from the third phase of the Optical Gravitational Lensing Experiment (OGLE-III) catalog. We also matched the OGLE-III SMC Cepheids to 2MASS and SAGE-SMC catalog to derive mean magnitudes in the JHK-bands and the four Spitzer IRAC bands, respectively. All photometry was corrected for extinction by adopting Zaritsky’s extinction map. Cepheids with periods smaller than ∼2.5 days were removed from the sample. In addition to the extinction corrected P–L relations in nine filters from optical to infrared, we also derived the extinction-free Wesenheit function for these Cepheids. We tested the nonlinearity of these SMC P–L relations (except the 8.0 μm-band P–L relation) at 10 days: none of the P–L relations show statistically significant evidence of nonlinearity. When compared to the P–L relations in the LMC, the t-test results revealed that there is a difference between the SMC/LMC P–L slopes only in the V- and J-band. Further, we found excellent agreement between the SMC/LMC Wesenheit P–L slope. The difference in LMC and SMC Period–Wesenheit relation LMC and SMC zero points was found to be Δμ=0.483±0.015 mag. This amounts to a difference in distance modulus between the LMC and SMC.

OSTI ID:
22882860
Journal Information:
Astrophysical Journal, Vol. 808, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; ISSN 0004-637X
Country of Publication:
United Kingdom
Language:
English