Oxford University Press;London: Oxford University Press
摘要:
摘要： We analyse Galactic, Large Magellanic Cloud and Small Magellanic Cloud Cepheids and RR Lyrae variables in terms of period–colour (PC) and amplitude–colour (AC) diagrams at the phases of maximum and minimum light. We compiled Galactic Cepheids V- and I-band data from the literature. We make use of optical bands light-curve data from OGLE-III survey for Cepheids and RR Lyrae variables in the Magellanic Clouds. We apply the F-statistical test to check the significance of any variation in the slope of PC and AC relations for Cepheid variables. The PC relation at maximum light for Galactic Cepheids with periods longer than about 7 d is shallow and the corresponding AC relation is flat for the entire period range. For the fundamental mode Cepheids in the Magellanic Clouds, we find significant breaks in the PC and AC relations at both maximum and minimum light for periods around 10 d. The PC relation at maximum light for the Magellanic Clouds is flat for Cepheids with periods greater than 10 d. First overtone Cepheids with periods less than 2.5 d have a shallow PC relation at minimum light. For fundamental mode RR Lyraes, we confirm earlier work supporting a flat PC relation at minimum light and a significant relation between amplitude and colour at maximum light. We find that no such relations exist for first overtone RR Lyrae stars. These findings are in agreement with stellar photosphere/hydrogen ionization front interaction considerations. These non-linearities can provide strong constraints for models of stellar pulsation and evolution. 其他題名： Mon. Not. R. Astron. Soc 出版者： London: Oxford University Press 出版日期： 2014-12-11 出處： Monthly notices of the Royal Astronomical Society, 2014-12, Vol.445 (3), p.2655-2666 資源來源： Alma/SFX Local Collection 版權： 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society 2014 版權： Copyright Oxford University Press, UK Dec 11, 2014 識別號： ISSN: 0035-8711 識別號： EISSN: 1365-2966 識別號： DOI: 10.1093/mnras/stu1941
