English

High-resolution Spectroscopy and Spectropolarimetry of Selected Delta Scuti Pulsating Variables

Solar and Stellar Astrophysics 2017-01-25 v1

Abstract

The combination of photometry, spectroscopy and spectropolarimetry of the chemically peculiar stars often aims to study the complex physical phenomena such as stellar pulsation, chemical inhomogeneity, magnetic field and their interplay with stellar atmosphere and circumstellar environment. The prime objective of the present study is to determine the atmospheric parameters of a set of Am stars to understand their evolutionary status. Atmospheric abundances and basic parameters are determined using full spectrum fitting technique by comparing the high-resolution spectra to the synthetic spectra. To know the evolutionary status we derive the effective temperature and luminosity from different methods and compare them with the literature. The location of these stars in the H-R diagram demonstrate that all the sample stars are evolved from the Zero-Age-Main-Sequence towards Terminal-Age-Main-Sequence and occupy the region of δ\delta Sct instability strip. The abundance analysis shows that the light elements e.g. Ca and Sc are underabundant while iron peak elements such as Ba, Ce etc. are overabundant and these chemical properties are typical for Am stars. The results obtained from the spectropolarimetric analysis shows that the longitudinal magnetic fields in all the studied stars are negligible that gives further support their Am class of peculiarity.

Keywords

Cite

@article{arxiv.1701.02891,
  title  = {High-resolution Spectroscopy and Spectropolarimetry of Selected Delta Scuti Pulsating Variables},
  author = {Santosh Joshi and Eugene Semenko and A. Moiseeva and Kaushal Sharma and Y. C. Joshi and M. Sachkov and Harinder P. Singh and Yerra Bharat Kumar},
  journal= {arXiv preprint arXiv:1701.02891},
  year   = {2017}
}

Comments

Accepted for publication in MNRAS