Powers and Magnetization of Blazar Jets

TL;DR

This paper reviews observational constraints on the energetics and magnetization of quasar jets, highlighting the significance of jet magnetization for particle acceleration mechanisms and spectral features in blazars.

Contribution

It demonstrates that a specific electron-positron to proton ratio implies significant jet magnetization, supporting magnetic reconnection as the primary particle acceleration process.

Findings

Jet magnetization in FSRQ is significant.

Reconnection mechanism is favored for particle acceleration.

High Compton-dominance explained without low magnetization.

Abstract

In this work I review the observational constraints imposed on the energetics and magnetisation of quasar jets, in the context of theoretical expectations. The discussion is focused on issues regarding the jet production efficiency, matter content, and particle acceleration. I show that if the ratio of electron-positron-pairs to protons is of order $15$, as is required to achieve agreement between jet powers computed using blazar spectral fits and those computed using radio-lobe calorimetry, the magnetization of blazar jets in flat-spectrum-radio-quasars (FSRQ) must be significant. This result favors the reconnection mechanism for particle acceleration and explains the large Compton-dominance of blazar spectra that is often observed, without the need to postulate very low jet magnetization.