Multi-frequency temporal and spectral variability study of blazar PKS 1424−418

Abstract

ABSTRACT A study of blazar PKS 1424−418 was carried out using multi-waveband data collected by the Fermi Large Area Telescope (Fermi-LAT), Swift X-Ray Telescope (Swift-XRT), Swift UltraViolet and Optical Telescope (Swift-UVOT), and Small and Moderate Aperture Research Telescope System (SMARTS) between MJD 56000 and MJD 56600 (2012 March 14–2013 November 4). Two flaring episodes were identified by analysing the gamma-ray light curve. Simultaneous multi-waveband spectral energy distributions (SEDs) were obtained for those two flaring periods. A cross-correlation analysis of infrared (IR)–optical and γ-ray data suggested that the emission originated from the same region. We have set a lower limit for the Doppler factor using the highest energy photon observed from this source during the flaring periods, which should be >12. The broad-band emission mechanism was studied by modelling the SED using the leptonic emission mechanism.