H.E.S.S. Monitoring of PKS 2155-304 in 2015 and 2016

Abstract

PKS 2155-304 is one of the brightest blazar located in Southern Hemisphere, monitored with H.E.S.S. since the first light of the experiment. Here we report multiwavelength monitoring observations collected during the period of 2015-2016 with H.E.S.S.,Fermi-LAT, Swift-XRT, Swift-UVOT, and ATOM. Two years of multiwavelength data with very good temporal coverage allowed to characterize broadband emission observed from the region of PKS 2155-304 and study potential multifrequency correlations. During the period of monitoring, PKS 2155-304 revealed complex multiwavelength variability with two outbursts characterized by completely different multiband properties. The 2015 activity of the blazar is characterized by a flare observed at all wavelengths studied. The broadband emission observed during the outburst is well correlated without any time lags. Contrary to 2015, in 2016, only orphan outburst in the optical and ultraviolet wavelengths was observed. Such an orphan activity is reported for the first time for the blazar PKS 2155-304.

10 pages, 2 figures, conference paper for the workshop "Monitoring the non-thermal Universe 2018" held in Cochem in September 2018

References in corpus (6)

• Observations of the Crab Nebula with H.E.S.S
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• Simultaneous observations of PKS 2155-304 with H.E.S.S., Fermi, RXTE and ATOM: spectral energy distributions and variability in a low state
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Cited by in corpus (4)

• A unified model for orphan and multi-wavelength blazar flares
• Correlation between optical and $\gamma$-ray flux variations in bright flat spectrum radio quasars
• 20 years of monitoring: PKS 2155-304 and PKS 1510-089 in the eyes of Swift and Fermi. I. The case of PKS 2155-304
• 20 years of monitoring: PKS 2155-304 and PKS 1510-089 in the eyes of Swift and Fermi. II. PKS 1510-089 and comparison