Simulations of Neutrino and Gamma-Ray Production from Relativistic Black-Hole Microquasar Jets

Abstract

Recently, microquasar jets have aroused the interest of many researchers focusing on the astrophysical plasma outflows and various jet ejections. In this work, we concentrate on the investigation of electromagnetic radiation and particle emissions from the jets of stellar black hole binary systems characterized by the hadronic content in their jets. Such emissions are reliably described within the context of relativistic magneto-hydrodynamics. Our model calculations are based on the Fermi acceleration mechanism through which the primary particles (mainly protons and electrons) of the jet are accelerated. As a result, a small portion of thermal protons of the jet acquire relativistic energies, through shock-waves generated into the jet plasma. From the inelastic collisions of fast (non-thermal) protons with the thermal (cold) ones, secondary charged and neutral particles (pions, kaons, muons, η-particles, etc.) are created, as well as electromagnetic radiation from the radio wavelength band to X-rays and even very high energy gamma-rays. One of our main goals is, through the appropriate solution of the transport equation and taking into account the various mechanisms that cause energy losses to the particles, to study the secondary particle concentrations within hadronic astrophysical jets. After assessing the suitability and sensitivity of the derived (for this purpose) algorithms on the Galactic MQs SS 433 and Cyg X-1, as a concrete extragalactic binary system, we examine the LMC X-1 located in the Large Magellanic Cloud, a satellite galaxy of our Milky Way Galaxy. It is worth mentioning that, for the companion O star (and its extended nebula structure) of the LMC X-1 system, new observations using spectroscopic data from VLT/UVES have been published a few years ago.

Relativistic Magnetized Astrophysical Plasma Outflows in Black-Hole Microquasars

“…In our previous works [7,9], we have adopted the proton-proton (p-p) interaction mechanism taking place inside the relativistic astrophysical outflows of microquasar jets. This also leads to the particle (pions, muons, neutrinos, etc.)…”

“…The observations of multi-wavelength and multi-particle emissions from the black-hole X-ray binaries (BHXRBs) [3][4][5] and the AGNs have shown that they are mainly due to the mass accretion onto the compact object (black hole or neutron star). The accreted matter comes from a companion (donor) star which is often a nearby main sequence star [6,7]. Thus, the inflow (from the companion star) into the accretion disc and the outflow in the jet motivate the investigation of the disc-jet connection [8] in the latter systems.…”

“…This is not restricted only in the analysis of the very large amount of observations [3][4][5]12] compared to emissions of smaller energy ranges but also in their advanced theoretical modeling [9][10][11]13,14]. Up to now, multidimensional numerical simulations and theoretical calculations have attempted to shed light on the nature of the interaction mechanisms as well as on the dynamics involved in the associated emissions [7,11]. They offer good support for experimental efforts of astrophysical particles and radiation detection (for more details the reader is referred to References [13,15]).…”

“…In this work, initially, we discuss some of the possible interactions resulting in secondary particle and radiation production. In our previous works, we have addressed the proton-proton (p-p) mechanism and estimated the respective energy distributions as well as the emissivities of neutrino and gamma-ray emissions [7,30,31]. In the current study, we concentrate on the proton-photon (p-γ) interaction mechanism and its dependence on geometric characteristics of the binary systems of our interest.…”

Modeling Simulated Emissions from Galactic Binary Stars

“…Several cooling mechanisms such as syncrotron emission, collisions with the rest of the jet matter and adiabatic jet expansion tend to stall the proton energetic boosting and set an upper limit for particle energy usually of the order E max ≈ 10 7 GeV for protons and secondary particles 6,7 . In previous works, we used this model for the neutrino and gamma-ray emission prediction from extragalactic system LMC X-1 8 .…”