Studying Intra-Night Optical Variability of AGNs Using the TESS Survey Data

Abstract

Active galactic nuclei (AGNs) exhibit significant luminosity variations across the entire electromagnetic spectrum, with timescales ranging from hours to years. Studying the optical variability of AGNs provides crucial insights into their physical properties. In this study, we explore the intra-night optical variability (INOV) of AGNs using data from the TESS satellite’s all-sky survey. We derive differential light curves for a sample of 56 AGNs from 30-min cadence TESS full-frame images. Our analysis confirms that BL Lac objects typically exhibit stronger INOV compared to quasars, which generally show weaker variability. The duty cycle for INOV with an amplitude greater than 3% is approximately 4±0.7% for quasars and 22±5% for BL Lac objects. For INOV with an amplitude exceeding 10%, the corresponding duty cycle decreases to about 0.5±0.3% and 5±2%, respectively. Furthermore, we identify a potential linear-log relationship between the duty cycle and the INOV amplitude, based on results from this study and previous findings, particularly from the ARIES program.