Baryon Loading Efficiency and Particle Acceleration Efficiency of Relativistic Jets: Cases for Low Luminosity BL Lacs
Abstract
Relativistic jets launched by supermassive black holes, so-called active galactic nuclei (AGNs), are known as the most energetic particle accelerators in the universe. However, the baryon loading efficiency onto the jets from the accretion flows and their particle acceleration efficiencies have been veiled in mystery. With the latest data sets, we perform multi-wavelength spectral analysis of quiescent spectra of 13 TeV gamma-ray detected high-frequency-peaked BL Lacs (HBLs) following one-zone static synchrotron self-Compton (SSC) model. We determine the minimum, cooling break, and maximum electron Lorentz factors following the diffusive shock acceleration (DSA) theory. We find that HBLs have {P}B/{P}e∼ 6.3× {10}-3 and the radiative efficiency {ɛ }{{rad,jet}}∼ 6.7× {10}-4, where P B and P e is the Poynting and electron power, respectively. By assuming 10 leptons per one proton, the jet power relates to the black hole mass as {P}{{jet}}/{L}{{Edd}}∼ 0.18, where {P}{{jet}} and {L}{{Edd}} is the jet power and the Eddington luminosity, respectively. Under our model assumptions, we further find that HBLs have a jet production efficiency of {η }{{jet}}∼ 1.5 and a mass loading efficiency of {ξ }{{jet}}≳ 5× {10}-2. We also investigate the particle acceleration efficiency in the blazar zone by including the most recent Swift/BAT data. Our samples ubiquitously have particle acceleration efficiencies of {η }g∼ {10}4.5, which is inefficient to accelerate particles up to the ultra-high-energy-cosmic-ray (UHECR) regime. This implies that the UHECR acceleration sites should not be the blazar zones of quiescent low power AGN jets, if one assumes the one-zone SSC model based on the DSA theory.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2016
- DOI:
- 10.3847/0004-637X/828/1/13
- arXiv:
- arXiv:1603.07623
- Bibcode:
- 2016ApJ...828...13I
- Keywords:
-
- BL Lacertae objects: general;
- galaxies: active;
- galaxies: jets;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 21 pages, 15 figures, Accepted for publication in ApJ. Various pair fraction cases are newly considered in the accepted version