Multi-wavelength Intra-day Variability and Quasi-periodic Oscillation in Blazars

TL;DR

This paper reviews multi-wavelength intra-day variability and rare quasi-periodic oscillations in blazars, highlighting their significance in understanding emission regions and black hole properties.

Contribution

It provides a comprehensive overview of intra-day variability and quasi-periodic oscillations across electromagnetic spectra in blazars, emphasizing their observational and theoretical implications.

Findings

Blazars exhibit intra-day variability across the entire electromagnetic spectrum.

Quasi-periodic oscillations are rare and primarily observed in optical and X-ray bands.

Intra-day variability constrains emission region sizes and black hole masses.

Abstract

We reviewed multi-wavelength blazars variability and detection of quasi-periodic oscillations on intra-day timescales. The variability timescale from few minutes to up to less than a days is commonly known as intra-day variability. These fast variations are extremely useful to constrain the size of emitting region, black hole mass estimation, etc. It is noticed that in general blazars show intra-day variability in the complete electromagnetic spectrum. But some class of blazars either do not show or show very little intra-day variability in a specific band of electromagnetic spectrum. Blazars show rarely quasi-periodic oscillations in time series data in optical and X-ray bands. Other properties and emission mechanism of blazars are also briefly discussed.