Hadronic signatures from magnetically dominated baryon-loaded AGN jets

Abstract

Blazars are a rare class of active galactic nuclei (AGN) with relativistic jets pointing towards the observer. Jets are thought to be launched as Poynting-flux dominated outflows that accelerate to relativistic speeds at the expense of the available magnetic energy. In this work, we consider electron-proton jets and assume that particles are energized via magnetic reconnection in parts of the jet where the magnetization is still high ($\sigma \ge 1$). The magnetization and bulk Lorentz factor $\Gamma$ are related to the available jet energy per baryon as $\mu =\Gamma (1+\sigma )$. We adopt an observationally motivated relation between $\Gamma$ and the mass accretion rate into the black hole $\dot{m}$, which also controls the luminosity of external radiation fields. We numerically compute the photon and neutrino jet emission as a function of $\mu$ and $\sigma$. We find that the blazar SED is produced by synchrotron and inverse Compton radiation of accelerated electrons, while the emission of hadronic-related processes is subdominant except for the highest magnetization considered. We show that low-luminosity blazars ($L_{\gamma }\lesssim 10^{45}$ erg s${}^{-1}$) are associated with less powerful, slower jets with higher magnetizations in the jet dissipation region. Their broadband photon spectra resemble those of BL Lac objects, and the expected neutrino luminosity is $L_{\nu +\bar{\nu }}\sim (0.3-1)L_{\gamma }$. High-luminosity blazars ($L_{\gamma }\gg 10^{45}$ erg s${}^{-1}$) are associated with more powerful, faster jets with lower magnetizations. Their broadband photon spectra resemble those of flat spectrum radio quasars, and they are expected to be dim neutrino sources with $L_{\nu +\bar{\nu }}\ll L_{\gamma }$.

16 pages, accepted for publication in MNRAS

References in corpus (21)

• Formation of Hard Power-laws in the Energetic Particle Spectra Resulting from Relativistic Magnetic Reconnection
• The power of blazar jets
• The power of relativistic jets is larger than the luminosity of their accretion disks
• Time-integrated Neutrino Source Searches with 10 years of IceCube Data
• Magnetic acceleration of relativistic AGN jets
• Relativistic Jets Shine through Shocks or Magnetic Reconnection?
• The blazar sequence: a new perspective
• A hadronic origin for ultra-high-frequency-peaked BL Lac objects
• MOJAVE. XVII. Jet Kinematics and Parent Population Properties of Relativistically Beamed Radio-Loud Blazars
• Relativistic Beaming and the Intrinsic Properties of Extragalactic Radio Jets
• Photohadronic origin of $\gamma$-ray BL Lac emission: implications for IceCube neutrinos
• TXS 0506+056, the first cosmic neutrino source, is not a BL Lac
• Bethe-Heitler emission in BL Lacs: filling the gap between X-rays and $\gamma$-rays
• The jet-disc connection in AGN
• Recent Progress on Particle Acceleration and Reconnection Physics during Magnetic Reconnectionin the Magnetically-dominated Relativistic Regime
• Beginning a journey across the universe: the discovery of extragalactic neutrino factories
• The Blazar sequence and its Physical Understanding
• Comprehensive Multimessenger Modeling of the Extreme Blazar 3HSP J095507.9+355101 and Predictions for IceCube
• The Spectra of IceCube Neutrino (SIN) candidate sources -- II. Source Characterisation
• The TeV emission of Ap Librae: a hadronic interpretation and prospects for CTA
• PKS 1424+240: yet another masquerading BL Lac object as a possible IceCube neutrino source

Cited by in corpus (3)

• Exploring the role of composition and mass-loading on the properties of hadronic jets
• Hillas meets Eddington: The case for blazars as ultra-high-energy neutrino sources
• Current sheet formation under radiative cooling