Mid-infrared variability of the neutrino source blazar TXS 0506$+$056

TL;DR

This study analyzes mid-infrared variability of the blazar TXS 0506+056 around a neutrino detection, revealing a significant brightening prior to the event, linked to jet activity in radio-loud AGN.

Contribution

First to investigate mid-infrared variability of TXS 0506+056 in relation to neutrino emission using WISE data.

Findings

30% brightening in mid-infrared bands prior to neutrino event

Detection of intraday infrared variability in 2010

Infrared variability linked to jet activity in radio-loud AGN

Abstract

The IceCube instrument detected a high-energy cosmic neutrino event on 2017 September 22 (IceCube_170922A, IceCube Collaboration 2018), which the electromagnetic follow-up campaigns associated with the flaring $\gamma$-ray blazar TXS 0506$+$056 (e.g., Padovani et al., 2018). We investigated the mid-infrared variability of the source by using the available single exposure data of the WISE satellite at $3.4$ and $4.6\mu$m. TXS 0506$+$056 experienced a $\sim 30$% brightening in both of these bands a few days prior to the neutrino event. Additional intraday infrared variability can be detected in 2010. Similar behaviour seen previously in $\gamma$-ray bright radio-loud AGN has been explained by their jet emission (e.g., Jiang et al. 2012).