Astronomical Jets Research Articles

Dynamic Universe Model Based on Newtonian Gravitation Giving Results Well from Universe Level to Galaxy Level to Solar System Level to Earth Level to Electron Level to Energy Level and to Nanobio Particle Level Now

Dynamic universe model’s SITA simulations can be used to solve many problems in physics, chemistry, Biology etc. The Dynamic Universe Model is based on Newtonian gravitation and finds the total attractive force of all masses in a combined way on any single mass. This SITA approach provides accurate results from the Universe level down to the Galaxy, Solar System, Earth, Electron, Energy, and even Nanobio Particle levels. Our thinking and exploration should not be limited to just 2-body problem and Universe model limited to cosmology in Physics. A small software program (SITA) takes your thinking to: - What are the inherent properties of inter-molecular attraction forces? - How does the Galaxy balance its rotations of stars? - Why did the Pioneer satellite have an irregular movement? - Why there are so many blue shifted Galaxies in the universe? - What is the structure of Galaxy center which will be stable and can support full Galaxy? - How insolvable contaminations in water or in any other liquids diffuse? - What happens to all the energy emitted by sun and other stars and Galaxies? - How local system of Galaxies balance each other? - How are electrons or positrons generated in the universe? - Exploring galaxy rotation curves - Can these be explained…the Origin, Propagation and Uniformity of CMB?? - How hydrogen atoms and other atoms are formed? - How are three states of water (H2O) formed? - How astronomical Jets are formed? - How are the mathematical equations proved? - What about SINGULARITIES in the software and in the Model?

Explaining Formation of Astronomical Jets Using Dynamic Universe Model

Astronomical jets are observed from the centres of many Galaxies including our own Milkyway. The formation of such jet is explained using SITA simulations of dynamic universe model. For this purpose the path traced by a test neutron is calculated and depicted using a set up of one densemass of the mass equivalent to mass of Galaxy center, 90 stars with similar masses of stars near Galaxy center, mass equivalents of 23 Globular Cluster groups, 16 Milkyway parts, Andromeda and Triangulum Galaxies at appropriate distances. Five different kinds of theoretical simulations gave positive results. The path travelled by this test neutron was found to be an astronomical jet emerging from Galaxy center.

Energetic and Broad Band Spectral Distribution of Emission from Astronomical Jets

Emission from astronomical jets extend over the entire spectral band: from radio to the TeV gamma-rays. This implies that various radiative processes are taking place in different regions along jets. Understanding the origin of the emission is crucial in understanding the physical conditions inside jets, as well as basic physical questions such as jet launching mechanism, particle acceleration and jet composition. In this chapter I discuss various radiative mechanisms, focusing on jets in active galactic nuclei (AGN) and X-ray binaries (XRB) environment. I discuss various models in use in interpreting the data, and the insights they provide.

OBSERVATIONS OF PARTICLE ACCELERATION IN THE BLAST WAVES OF GAMMA-RAY BURSTS

The electron energy distribution index, p, is a fundamental parameter of the process by which electrons at shock fronts are accelerated to relativistic speeds and by which they radiate, via synchrotron emission. This acceleration process is applicable to a myriad of astronomical jet sources such as AGN, X-ray binaries and gamma-ray bursts (GRBs), as well as to particle acceleration in the solar wind and supernovae, and the acceleration of cosmic rays. The accurate measurement of the distribution of p is of fundamental importance to differentiate between the possible theories of electron acceleration at any relativistic shock front; there is division as to whether p has a universal value or whether it has a distribution, and if so, what that distribution is. Here one such source of synchrotron emission is examined: the blast waves of GRB afterglows observed by the Swift satellite. Within the framework of the GRB blast wave model, the constraints placed on the distribution of p by the observed X-ray spectral and temporal indices are examined and the distribution parametrized. The results show that the observed distribution of spectral indices is inconsistent with an underlying distribution of p composed of a single discrete value but consistent with a Gaussian distribution centred at p = 2.4 and having a width of 0.6. This finding disagrees with theoretical work that argues for a single, universal value of p, but also demonstrates that the width of the distribution is not as wide as has been suggested by some authors.

Electromagnetic fields in jets

The magnetic fields and energy flows in an astronomical jet described by our earlier model are calculated in detail. Though the field distribution varies with the external pressure function p(z), it depends only weakly on the other boundary conditions. Individual fieldlines were plotted; the lines become nearly vertical at the bottom and are twisted at the top. An animation of a fieldline's motion was made, which shows the line being wound up by the accretion disc's differential rotation and rising as a result of this. The distribution of Poynting flux within the jet indicates that much of the energy flows up the jet from the inside of the accretion disc but a substantial fraction flows back down to the outside.

Collimation mechanism of magnetohydrodynamic jets based on helicity and cross-helicity dynamos, with reference to astronomical jets

A collimation mechanism of magnetohydrodynamic jets is sought on the basis of the turbulent-dynamo theory within the framework of fluid incompressibility. The momentum diffusion giving rise to the broadening of the jets is suppressed through the cross-helicity effect, whereas the diffusion of the magnetic field is hampered owing to the helicity effect. These two effects lead to the collimation of electrically conducting jets in the presence of turbulent fluctuations of the velocity and magnetic field. The relevance to collimated astronomical jets is discussed with the reservation about effects of fluid compressibility.

Region of Magnetic Dominance near a Rotating Black Hole

This is a brief contribution in which a simplified criterion of the relevance of the test-particle approximation describing motion of material near a magnetized black hole is discussed. Application to processes of the dissipative collimation of astronomical jets (as proposed by de Felice and Curir, 1992) is mentioned.

Dynamics of wind bubbles and superbubbles. I - Slow winds and fast winds. II - Analytic theory

The paper describes the overall evolution of wind-blown bubbles in a uniform medium from the initial, free-expansion stage to the final stage in which the pressure of the ambient medium is significant. The concepts of slow and fast winds, which naturally arise from consideration of radiative losses at the free-expansion stage, are introduced. The evolution of bubbles in a plane-parallel disk, where the density decreases steeply along a vertical direction, is considered. The questions of when a bubble can break out of a thin galactic disk and how they evolve after the breakout are discussed. After breakout, bubbles can evolve into jets. Steady, collimated jets can form only over a limited range of wind luminosity and Mach number; astronomical jets are likely to be unsteady and/or hydromagnetic. The results are applied to the neutral stellar wind in the HH 7-11 region, to the north polar spur, and to the galactic winds in starburst galaxies. The evolution of wind-blown bubbles in a power-law density distribution is investigated. Characteristic evolutionary time scales, as well as the equation of motion for both the swept-up gas and the wind shock in each evolutionary stage are obtained.

Astronomical jet engines

Astronomical jet engines