# Long term study of the light curve of PKS 1510-089 in GeV energies

## TL;DR

This 8-year study of PKS 1510-089's gamma-ray light curve reveals multiple flares, detailed temporal and spectral analysis, and insights into the emission region's size and spectral characteristics, advancing understanding of blazar variability.

## Contribution

First long-term detailed temporal and spectral analysis of PKS 1510-089's gamma-ray flares using Fermi-LAT data, identifying key flare features and spectral behaviors.

## Key findings

- Identified five major flares and sub-structures.
- Fastest variability time of approximately 1.3 hours.
- Spectral energy distributions favor Logparabolic fits.

## Abstract

We have analyzed data from the Flat Spectrum Radio Quasar PKS 1510-089 collected over a period of 8 years from August 2008 to December 2016 with the Fermi-LAT. We have identified several flares of this highly variable source, studied their temporal and spectral properties in detail and compared with previous works on flares of PKS 1510-089. Five major flares and few sub-flares/sub-structures have been identified in our study. The fastest variability time is found to be 1.30$\pm$0.18 hr between MJD 55852.063 and 55852.188 where we estimate the minimum size of the emission region to be $4.85 \times 10^{15}$ cm. In most of the flares the spectral energy distributions are better fitted with Logparabolic distribution compared to simple Power law or Power law with exponential cut-offs. This has strong physics implications regarding the nature of the high energy gamma-ray emission region.