The Correlated Multi-color Optical Variations of BL Lac Object S5 0716+714

TL;DR

This study investigates the correlated optical flux variations of BL Lac object S5 0716+714, revealing strong correlations and potential short time lags between different optical bands, which inform emission process models.

Contribution

It provides the first detailed analysis of inter-band optical flux correlations and potential time lags in S5 0716+714 using DCF and Monte Carlo methods.

Findings

Strong correlations among optical bands.

Possible time lag of a few minutes with higher frequency leading.

Methodology confirms correlation significance.

Abstract

S5 0716+714 is a well-studied BL Lac object in the sky. Verifying the existence of correlations among the flux variations in different bands serves as an important tool to investigate the emission processes. To examine the possible existence of a lag between variations in different optical bands on this source, we employ a discrete correlation function (DCF) analysis on the light curves. In order to obtain statistically meaningful values for the cross-correlation time lags and their related uncertainties, we perform Monte Carlo simulations called "flux redistribution/random subset selection" (FR/RSS). Our analysis confirms that the variations in different optical light curves are strongly correlated. The time lags show a hint of the variations in high frequency band leading those in low frequency band of the order of a few minutes.