| Authors : | Kerdaris Kurbah, Department of Physics, Cotton University, Guwahati 781001,
Assam, India, e-mail: kerdarisbahkur@gmail.com
Sukanta Deb, Department of Physics, Cotton University, Guwahati 781001,
Assam, India, e-mail:sukanta.deb@cottonuniversity.ac.in
Shashi M. Kanbur, Department of Physics, State University of New York, Oswego, NY 23126, USA, e-mail:shashi.kanbur@oswego.edu
Susmita Das, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Eötvös Loránd Research Network (ELKH), Konkoly-Thege Miklós út 15-17, H-1121,\\ Budapest, Hungary
Mami Deka, Department of Physics, Cotton University, Guwahati 781001,
Assam, India
Anupam Bhardwaj, INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-801301, Napoli, Italy |
| Abstract : | We carried out an analysis of the theoretical and observed light curves of the fundamental mode (FU) classical Cepheids in the Magellanic Clouds. The observed light curves are taken from the OGLE-IV database, available in (?, ?)-bands for both the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC). Theoretical light curves in (?, ?)-bands across the four
convection sets are obtained using state-of-the-art 1D non-linear radial stellar pulsation (RSP) code in MESA (MESA-RSP), for two chemical compositions: ? = 0.008, ? = 0.742 and ? = 0.004, ? = 0.746, appropriate for the LMC and SMC, respectively. A comparative study of the Fourier Parameters (FPs) as a function of period and the multi-phase Period Luminosity (MPPL)
relations for short periods (log ? < 1), long periods (log ? > 1) and all periods obtained from theory and observations are carried out. It has been observed that there is an overlap among convection sets in the FP plane, however, a clear distinction is seen in the MPPL plane for most of the phases. MPPL relations obtained from theory as well as observations are found to be dynamic
in nature, with the effect more pronounced at Φ ∼ 0.75 − 0.85. Furthermore, a contrasting behaviour of the theoretical/observed MPPL relations obtained using short and long periods is observed for both LMC and SMC. It is interesting to note that the MPPL plane is more rigorous in comparing theory and observations than the FP plane, thus provides a new way to constrain theory of stellar pulsation. |
