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

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.

Inherent and Local Magnetic Field Structures in Jets from Active Galactic Nuclei

In theoretical models for the electromagnetic launching of astrophysical jets, a helical magnetic (B)-field component is generated through the winding up of an initial longitudinal field component by the rotation of the cental black hole and accretion disk. This helical field component travels outward with the jet plasma. There is now abundant evidence that the jets of active galactic nuclei carry helical B fields, and the presence of such fields has been invoked to explain a wide range of phenomena observed in these jets. However, distinguishing between features associated with this inherent jet B field and with B fields generated by local phenomena such as shocks and shear can be challenging. There is now evidence that the field that is accreted is dipolar like, giving rise to a current distribution with inward currents along both jet axes and outward currents in a more extended region around the jets. Striking limb brightening has been observed for several relatively nearby active galactic nuclei; it is argued that this must be due to some intrinsic property of the jet, which is independent of the viewing angle, such as its helical B field, or mass loading and/or particle acceleration at the jet edges. Circular-polarization observations may make it possible to reconstruct the full three-dimensional B field of jets carrying a helical B-field component, and to correctly infer the direction of rotation of the central black hole and its accretion disk.

On the Electromagnetic Vacuum Origins of Dark Energy, Dark Matter, and Astrophysical Jets

We use a semiclassical version of the Nexus paradigm of quantum gravity in which the quantum vacuum at large scales is dominated by the second quantized electromagnetic field to demonstrate that a virtual photon field can affect the geometric evolution of Einstein manifolds or Ricci solitons. This phenomenon offers a cogent explanation of the origins of astrophysical jets, the cosmological constant, and a means of detecting galactic dark matter.

Laboratory disruption of scaled astrophysical outflows by a misaligned magnetic field

The shaping of astrophysical outflows into bright, dense, and collimated jets due to magnetic pressure is here investigated using laboratory experiments. Here we look at the impact on jet collimation of a misalignment between the outflow, as it stems from the source, and the magnetic field. For small misalignments, a magnetic nozzle forms and redirects the outflow in a collimated jet. For growing misalignments, this nozzle becomes increasingly asymmetric, disrupting jet formation. Our results thus suggest outflow/magnetic field misalignment to be a plausible key process regulating jet collimation in a variety of objects from our Sun’s outflows to extragalatic jets. Furthermore, they provide a possible interpretation for the observed structuring of astrophysical jets. Jet modulation could be interpreted as the signature of changes over time in the outflow/ambient field angle, and the change in the direction of the jet could be the signature of changes in the direction of the ambient field.

Quantum magnetic collapse of a partially bosonized npe-gas: Implications for astrophysical jets

We study the quantum magnetic collapse of a partially bosonized [Formula: see text]-gas and obtain that this type of collapse might be one of the mechanisms behind matter expulsion out of compact objects. We check also that this gas might form a stable stream of matter whose collimation is due to its strong self-generated magnetic field. Possible astrophysical applications of these results, in particular related to jet formation and its maintenance, are discussed.