Abstract Details
| Name: Susmita Das Affiliation: University of Delhi Conference ID: ASI2017_815 Title : A Comparative Analysis of Theoretical and Observed light curves of RR Lyrae variables Authors and Co-Authors : Susmita Das (Department of Physics & Astrophysics, University of Delhi, Delhi 110007, India.), Harinder P. Singh (Department of Physics & Astrophysics, University of Delhi, Delhi 110007, India.), Shashi M. Kanbur (State University of New York, Oswego, NY 13126, USA.), Marcella Marconi (INAF-Osservatorio astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli, Italy), Anupam Bhardwaj (Department of Physics & Astrophysics, University of Delhi, Delhi 110007, India.) Abstract Type : Poster Abstract Category : Stars,ISM and the Galaxy Abstract : We study the comparison of new nonlinear, time- dependent convective hydrodynamical models of RR Lyrae stars computed using a constant helium-to-metal abundance ratio (Marconi et al. 2015) and observed light curves in the optical (UBVRI) and near-infrared (JKL) bands. The models used from the theoretical data are of metal abundance Z=0.02, Z=0.008 and Z=0.004 which correspond to the chemical compositions of Galaxy, LMC and SMC, respectively. We compare the PL, PC and AC relations of LMC and SMC in V and I bands with the corresponding theoretical data. The PL slope at minimum light of observed RR Lyrae data is -2.574±0.03 and that of theoretical is -2.276±0.383, for LMC in I-band. Corresponding intercept values are 18.32±0.007 and 18.515±0.094, respectively. Similar comparative relations were found for LMC and SMC at minimum, mean and maximum lights for V- and I-bands. We use the Fourier Decomposition Technique for the quantitative analysis of the light curves. The Fourier amplitude and phase parameters are compared. The theoretical phase parameters suggest an increase with period and then a subsequent decrease, with a maximum at log P = -0.2 (P=0.63 days), which is consistent with the observed phase parameters, for both LMC and SMC in V- and I-bands. This suggests a break in PL relation at around P=0.63 days. |