Proton Synchrotron $\gamma$-rays and the Energy Crisis in Blazars

Understand

The origin of high-energy emission in blazars jets (i.e., leptonic versus hadronic) has been a long-standing matter of debate.

• Here, we focus on one variant of hadronic models where proton synchrotron radiation accounts for the observed steady $\gamma$-ray blazar emission.
• Using analytical methods, we derive the minimum jet power ($P_{j,\min}$) for the largest blazar sample analyzed to date (145 sources), taking into account uncertainties of observables and jet's physical parameters.
• We compare $P_{j,\min}$ against three characteristic energy estimators for accreting systems, i.e., the Eddington luminosity, the accretion disk luminosity, and the power of the Blandford-Znajek process, and find that $P_{j,\min}$ is about 2 orders of magnitude higher than all energetic estimators for the majority of our sample.