# The High-energy emission of jetted AGN

## TL;DR

This paper investigates the high-energy emission mechanisms of jetted AGN, especially the role of inverse Compton scattering of CMB photons, and discusses their implications for galaxy evolution and black hole energetics.

## Contribution

It demonstrates that X-ray jets in AGN are primarily due to inverse Compton scattering of CMB photons and estimates the jet energetics and black hole spin requirements.

## Key findings

- X-ray jets are common in flat-spectrum radio quasars.
- Inverse Compton scattering of CMB explains X-ray emission with minimal parameters.
- Jet power can be supplied by black hole spin energy.

## Abstract

Quasars with flat radio spectra and one-sided, arc-second scale, ~100 mJy GHz radio jets are found to have similar scale X-ray jets in about 60% of such objects, even in short 5 to 10 ks Chandra observations. Jets emit in the GHz band via synchrotron radiation, as known from polarization measurements. The X-ray emission is explained most simply, i.e. with the fewest additional parameters, as inverse Compton (iC) scattering of cosmic microwave background (CMB) photons by the relativistic electrons in the jet. With physics based assumptions, one can estimate enthalpy fuxes upwards of 10^46 erg s$^{-1}$, suffcient to reverse cooling flows in clusters of galaxies, and play a signifcant role in the feedback process which correlates the masses of black holes and their host galaxy bulges. On a quasar-by-quasar basis, we can show that the total energy to power these jets can be supplied by the rotational energy of black holes with spin parameters as low as a = 0.3. For a few bright jets at redshifts less than 1, the Fermi gamma ray observatory shows upper limits at 10 Gev which fall below the fluxes predicted by the iC/CMB mechanism, proving the existence of multiple relativistic particle populations. At large redshifts, the CMB energy density is enhanced by a factor (1+z)^4, so that iC/CMB must be the dominant mechanism for relativistic jets unless their rest frame magnetic field strength is hundreds of micro-Gauss.