Smoothed Temporal Variance Spectrum: weak line profile variations and NRP diagnostics

TL;DR

This paper introduces the smoothed Temporal Variance Spectrum (smTVS) method for detecting ultra weak line profile variations in noisy stellar spectra and discusses its application in identifying non-radial pulsations and rotational effects.

Contribution

It presents an enhanced TVS method with pre-smoothing to improve detection of weak spectral variations and provides techniques to estimate NRP modes considering rotational modulation.

Findings

smTVS effectively detects ultra weak line profile variations in noisy data

The method allows estimation of non-radial pulsation modes

Analysis of rotational modulation influence on spectral variability

Abstract

We describe the version of the Temporal Variance Spectrum (TVS, Fullerton, Gies & Bolton 1996) method with pre-smoothed line profile (smoothed Temporal Variance Spectrum, smTVS). This method introduced by Kholtygin et al. (2003) can be used to detect the ultra weak variations of the line profile even for very noisy stellar spectra. We also describe how to estimate the mode of the non-radial pulsations (NRP) using the TVS and smTVS with different time spans. The influence of the rotational modulation of the line profile on the TVS is considered. The analysis of the contribution of NRP and rotational modulation in the global TVS is studied.