Jul 12 – 23, 2021
Europe/Berlin timezone

Confronting observations of VHE gamma-ray blazar flares with reconnection models

Jul 15, 2021, 12:00 PM
1h 30m


Talk GAI | Gamma Ray Indirect Discussion


Jenni Jormanainen


Several models have been suggested to explain the fast gamma-ray variability observed in blazars, but its origin is still debated. One scenario is magnetic reconnection, a process that can efficiently convert magnetic energy to energy of relativistic particles accelerated in the reconnection layer. In our study, we compare results from state-of-the-art particle-in-cell simulations with observations of blazars at Very High Energy (VHE, E > 100 GeV). Our goal is to test our model predictions on fast gamma-ray variability with data and to constrain the parameter space of the model, such as the magnetic field strength of the unreconnected plasma and the reconnection layer orientation in the blazar jet. For this first comparison, we used the remarkably well-sampled VHE gamma-ray light curve of Mrk 421 observed with the MAGIC and VERITAS telescopes in 2013. The simulated VHE light curves were generated using the observable parameters of Mrk 421, such as the jet power, bulk Lorentz factor, and the jet viewing angle, and sampled as real data. Our results pave the way for future model-to-data comparison with next-generation Cherenkov telescopes, which will help further constrain the different variability models.


AGN; blazars; VHE gamma-rays; fast variability; magnetic reconnection; jets

Subcategory Experimental Results

Primary authors

Jenni Jormanainen Talvikki Hovatta (Aalto University and Tuorla observatory, Finland) Elina Lindfors Maria Petropoulou Petropoulou (Princeton University) Dr Ian Christie (Northrop Grumman) Dr Ioannis Liodakis (Finnish Center for Astronomy with ESO)

Presentation materials