English
Related papers

Related papers: Cosmic Jets

200 papers

In certain general relativistic time-dependent gravitational fields, free test particles can asymptotically line up relative to fiducial static observers and produce a cosmic jet whose speed approaches the speed of light. Two scenarios for…

General Relativity and Quantum Cosmology · Physics 2025-06-10 Bahram Mashhoon

Consider a dynamic general relativistic spacetime in which the proper infinitesimal interval along one spatial coordinate direction decreases monotonically with time, while the corresponding intervals increase along other spatial…

General Relativity and Quantum Cosmology · Physics 2022-08-17 Donato Bini , Carmen Chicone , Bahram Mashhoon

In dynamic spacetimes in which asymmetric gravitational collapse/expansion is taking place, the timelike geodesic equation appears to exhibit an interesting property: Relative to the collapsing configuration, free test particles undergo…

General Relativity and Quantum Cosmology · Physics 2011-07-05 C. Chicone , B. Mashhoon , K. Rosquist

We investigate the asymptotic behavior of peculiar velocities in certain physically significant time-dependent gravitational fields. Previous studies of the motion of free test particles have focused on the \emph{collapse scenario},…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Donato Bini , Bahram Mashhoon

We present a family of dynamic rotating cylindrically symmetric Ricci-flat gravitational fields whose geodesic motions have the structure of gravitomagnetic jets. These correspond to helical motions of free test particles up and down…

General Relativity and Quantum Cosmology · Physics 2011-03-22 C. Chicone , B. Mashhoon

We investigate the motion of free relativistic particles relative to the ambient medium around a gravitationally collapsed system. If the relative speed exceeds a critical value given by c/sqrt(2), the gravitational tidal effects exhibit…

Astrophysics · Physics 2009-11-10 C. Chicone , B. Mashhoon

Exact plane gravitational radiation fields are presented within the framework of general relativity and their properties are described. The physics of nonlinear elliptically polarized plane gravitational waves is developed in close analogy…

General Relativity and Quantum Cosmology · Physics 2025-05-14 Masoud Molaei , Shant Baghram , Bahram Mashhoon

We study a simple class of time-dependent rotating Ricci-flat cylindrically symmetric spacetime manifolds whose geodesics admit gravitomagnetic jets. The helical paths of free test particles in these jets up and down parallel to the…

General Relativity and Quantum Cosmology · Physics 2015-03-17 C. Chicone , B. Mashhoon

Within the framework of general relativity, we investigate the tidal acceleration of astrophysical jets relative to the central collapsed configuration ("Kerr source"). We neglect electromagnetic forces throughout. The rest frame of the…

General Relativity and Quantum Cosmology · Physics 2020-12-29 Donato Bini , Carmen Chicone , Bahram Mashhoon

The current understanding of the formation of powerful bi-directional jets in systems such as radio galaxies and quasars is that the process involves a supermassive black hole that is being fed with magnetized gas through an orbiting…

High Energy Astrophysical Phenomena · Physics 2009-03-25 C Sivaram , Kenath Arun

We briefly review the known properties of Melvin's magnetic universe and study the propagation of test charged matter waves in this static spacetime. Moreover, the possible correspondence between the wave perturbations on the background…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Donato Bini , Bahram Mashhoon

In this chapter, we review some features of particle acceleration in astrophysical jets. We begin by describing four observational results relating to the topic, with particular emphasis on jets in active galactic nuclei and parallels…

High Energy Astrophysical Phenomena · Physics 2020-11-11 James Matthews , Anthony Bell , Katherine Blundell

Jets are observed in young stellar objects, X-ray sources, active galactic nuclei (AGN). The mechanisms of jet formation may be divided in regular, acting continuously for a long time, and explosive ones. Continuous mechanisms are related…

High Energy Astrophysical Phenomena · Physics 2019-05-16 G. S. Bisnovatyi-Kogan

Based on the set of nonlinear coupling equations describing the interaction of the high-frequency field, the self-generated magnetic field and the ion-acoustic field, the dispersion relation for the circular magnetic field is obtained. The…

Plasma Physics · Physics 2022-10-31 X. L. Liu , X. Q. Li

We perform full 3D numerical simulations of compact objects, such as black holes or neutron stars, boosted through an ambient force-free plasma that posses a uniform magnetization. We study jet formation and energy extraction from the…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Ramiro Cayuso , Federico Carrasco , Barbara Sbarato , Oscar Reula

Observations suggest that relativistic particles play a fundamental role in the dynamics of jets emerging from active galactic nuclei as well as in their interaction with the intracluster medium. However, no general consensus exists…

High Energy Astrophysical Phenomena · Physics 2015-06-11 J. A. de Freitas Pacheco , J. Gariel , G. Marcilhacy , N. O. Santos

Jet formation is connected most probably with matter acceleration from the vicinity of rotating magnetized bodies. It is usually related to the mass outflows and ejection from accretion disks around black holes. Problem of jet collimation…

Astrophysics · Physics 2009-11-06 G. S. Bisnovatyi-Kogan , N. V. Ardeljan , S. G. Moiseenko

We present a model of the gravitational field based on two symmetric tensors. The equations of motion of test particles are derived: Massive particles do not follow a geodesic but massless particles trajectories are null geodesics of an…

General Relativity and Quantum Cosmology · Physics 2015-05-19 J. Alfaro

We show how the motion of free material test particles in arbitrary spatial flows is easily determined within the context of ordinary vector calculus. This may be useful for everyone, including engineers and other non-specialists, when…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Tom Martin

We consider effects on an (ultra-) relativistic jet and its ambient medium caused by high energy cosmic rays accelerated at the jet side boundary. As illustrated by simple models, during the acceleration process a flat cosmic ray…

Astrophysics · Physics 2009-10-31 M. Ostrowski
‹ Prev 1 2 3 10 Next ›