Optical intraday variability analysis for the BL Lacertae object 1ES 1426+42.8

TL;DR

This study analyzes intraday variability in the blazar 1ES 1426+42.8 using optical observations, detecting a possible quasi-periodic oscillation and explaining the variability through a turbulent jet model and magnetic reconnection processes.

Contribution

It provides the first detailed analysis of IDV in 1ES 1426+42.8 using optical data and introduces a turbulent model to explain the variability and QPO phenomena.

Findings

Detected intraday variability on seven nights.

Identified a possible QPO of ~58.55 minutes with >3σ significance.

Observed period shortening from 54.23 to 29.71 minutes, possibly due to magnetic reconnections.

Abstract

The observation data of blazar 1ES 1426 + 42.8 were obtained using the 1.02 m optical telescope of Yunnan Observatories during $2021$ to $2023$. Intraday variability (IDV) is detected on seven nights. We use the turbulent model to investigate the mechanism of IDV in 1ES 1426 + 42.8. The fitting light curves match the actual IDV curves well. Using this model, we obtain the parameters such as the size of turbulent cells and the width of pulses in the jet. A possible short-lived Quasi-periodic oscillation (QPO) of $58.55 \pm 8.09$ minutes was detected on April 26, 2022 whose light curve exhibits eight cycles at $>3\sigma$ global significance and confirmed by several different techniques. Through a more detailed analysis of the light curve of this night, we find that the period is shortened from 54.23 minutes ($4\sigma$) to 29.71 minutes ($3\sigma$). The possible QPO and period shortening phenomenon are best explained by the processes of magnetic reconnections.