Oxford University Press;London: Oxford University Press
摘要:
摘要： We present multiband Period–Luminosity (PL) relations for first-overtone mode Cepheids in the Small Magellanic Cloud (SMC). We derive optical band PL relations and the Wesenheit function using VI mean magnitudes from the Optical Gravitational Lensing Experiment (OGLE-III) survey. We cross-match OGLE-III first-overtone mode Cepheids to the 2MASS and SAGE-SMC catalogues to derive PL relations at near-infrared (JHK s ) and mid-infrared (3.6 and 4.5 μm) wavelengths. We test for possible non-linearities in these PL relations using robust statistical tests and find a significant break only in the optical band PL relations at 2.5 d for first-overtone mode Cepheids. We do not find statistical evidence for a non-linearity in these PL relations at 1 d. The multiband PL relations for fundamental-mode Cepheids in the SMC also exhibit a break at 2.5 d. We suggest that the period break around 2.5 d is related to sharp changes in the light-curve parameters for SMC Cepheids. We also derive new optical and mid-infrared band PL relations for first-overtone mode Cepheids in the Large Magellanic Cloud (LMC). We compare multiband PL relations for first-overtone mode Cepheids in the Magellanic Clouds and find a significant difference in the slope of the V-band PL relations but not for I-band PL relations. The slope of PL relations are found to be consistent in most of the infrared bands. A relative distance modulus of Δμ = 0.49 ± 0.02 mag between the two clouds is estimated using multiband PL relations for the first-overtone mode Cepheids in the SMC and LMC. 出版者： London: Oxford University Press 出版日期： 2016-06-01 出處： Monthly notices of the Royal Astronomical Society, 2016-06, Vol.458 (4), p.3705-3719 資源來源： Alma/SFX Local Collection 版權： 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society 2016 版權： Copyright Oxford University Press, UK Jun 1, 2016 識別號： ISSN: 0035-8711 識別號： ISSN: 1365-8711 識別號： ISSN: 1365-2966 識別號： EISSN: 1365-2966 識別號： DOI: 10.1093/mnras/stw579
