A Time-Series Analysis of the H-alpha Emission Line in V3885 Sagitarii

TL;DR

This study analyzes the flickering behavior of the H-alpha emission line and continuum in the cataclysmic variable V3885 Sgr, revealing correlated variability and characteristic timescales through statistical and spectral analysis.

Contribution

It provides a detailed analysis of flickering in V3885 Sgr, combining statistical, autocorrelation, and cross-correlation methods to characterize emission line and continuum variability.

Findings

Flickering timescales are approximately 25-40 minutes.

Power spectra show stochastic behavior consistent with random events.

Correlation exists between H-alpha line variability and underlying continuum.

Abstract

Flickering is a phenomenon related to the mass accretion observed among many classes of astrophysical objects. In this paper we present a study of the flickering emission lines and continuum of the Cataclysmic Variable V3885 Sgr. The flickering behavior is first analyzed through statistical analysis and lightcurves power spectra. Autocorrelation techniques are then employed to estimate the flickering flares timescales. A cross correlation study between the line and its underlying continuum variability is presented. The cross correlation between the photometric and spectroscopic data is also discussed. The periodograms, calculated using emission line data, show a behavior that is similar to those obtained from photometric datasets found in the literature, with a plateau at lower frequencies and a power law at higher frequencies. The power law index is consistent with stochastic events. The cross-correlation study indicates the presence of a correlation between the variability on H-alpha and its underlying continuum. Flickering timescales derived from the photometric data were estimated as 25 minutes for two lightcurves and 10 minutes for one of them. The average timescales of the line flickering is 40 minutes, while for its underlying continuum it drops to 20 minutes.