Relativistic Jet Properties of GeV-TeV Blazars and Possible Implications for the Jet Formation, Composition, and Cavity Kinematics

TL;DR

This study models the spectral energy distributions of GeV-TeV blazars to analyze jet properties, revealing differences between FSRQs and BL Lacs in jet composition, power, and formation mechanisms, with implications for jet physics and cavity energetics.

Contribution

It provides the first detailed comparison of jet power, composition, and formation mechanisms between FSRQs and BL Lacs using SED modeling and jet-cavity correlations.

Findings

FSRQ jets are Poynting flux dominated with high radiation efficiency.

Jet power correlates with black hole mass in FSRQs but not in BL Lacs.

Magnetic fields and cold protons play key roles in jet-cavity energy transfer.

Abstract

We fit the spectral energy distributions (SEDs) of a GeV-TeV FSRQ sample with the leptonic model. Their gamma_min of the relativistic electron distributions, which significantly affect the estimates of the jet properties, are constrained, with a typical value of 48. Their jet power, magnetized parameter, radiation efficiency, and jet production/radiation rates per central black hole (BH) mass are derived and compared to that of BL Lacs. We show that he FSRQ jets may be dominated by the Poynting flux and have a high radiation efficiency, whereas the BL Lac jets are likely dominated by particles and have a lower radiation efficiency than FSRQs. Being different from BL Lacs, the jet powers of FSRQs are proportional to their central BH masses. The jet production and radiation rates of the FSRQs distribute in narrow ranges and are correlated with each other, whereas no similar feature is found for the BL Lacs. We also show that the jet power is correlated with the cavity kinetic power, and the magnetic field energy in the jets may provide the cavity kinetic energy of FSRQs and the kinetic energy of cold protons in the jets may be crucial for cavity kinetic energy of BL Lacs. We suggest that the dominating formation mechanism of FSRQ jets may be the BZ process, but BL Lac jets may be produced via the BP and/or BZ processes, depending on the structures and accretion rates of accretion disks.