Multiwavelength flaring activity of PKS1510-089

TL;DR

This study investigates the multiwavelength flaring activity of PKS1510-089, revealing correlations between radio, optical, and gamma-ray flares, supporting a shock-in-jet model for emission source locations.

Contribution

It provides multiwavelength observational evidence and interprets the flaring activity within a shock-in-jet framework, constraining emission region locations.

Findings

Detected a 54-day delay between radio and gamma-ray flares.

Observed large polarization angle rotations associated with gamma-ray flares.

Supported the shock-in-jet model explaining multiwavelength variability.

Abstract

Aims: In this work, we analyse the multiwavelength brightness variations and flaring activity of FSRQ PKS1510-089, aiming to constrain the position of the emission sources. Methods: We report 7 mm (43 GHz) radio and R-band polarimetric observations of PKS1510-089. The radio observations were performed at the Itapetinga Radio Observatory, while the polarimetric data were obtained at the Pico dos Dias Observatory. The 7 mm observations cover the period between 2011 and 2013, while the optical polarimetric observations were made between 2009 and 2012. Results: At 7 mm, we detected a correlation between four radio and $\gamma$-ray flares with a delay of about 54 days between them; the higher frequency counterpart occurred first. Using optical polarimetry, we detected a large variation in polarization angle (PA) within two days associated with the beginning of a $\gamma$-ray flare. Complementing our data with other data obtained in the literature, we show that PA presented rotations associated with the occurrence of flares. Conclusions: Our results can be explained by a shock-in-jet model, in which a new component is formed in the compact core producing an optical and/or $\gamma$-ray flare, propagates along the jet, and after some time becomes optically thin and is detected as a flare at radio frequencies. The variability in the polarimetric parameters can also be reproduced; we can explain large variation in both PA and polarization degree (PD), in only one of them, or in neither, depending on the differences in PA and PD between the jet and the new component.