We report on a study of the time sequence for the appearance of highvelocity jets and equatorial tori in the transition of stars from the asymptotic giant branch to the planetary nebulae phase. Jets and tori are prominent features of this evolution, but their origins are uncertain. Using the kinematics of molecular tori and molecular or optical jets, we determine the ejection histories for a sa...

The jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading a differentially rotating accretion disk which acts to magnetically extract angular momentum and energy from the disk. Two main regimes have been discussed, hydromagnetic jets, which have a significant mass flux and have energy and angular momentum carried by both matter an...

Gamma-ray emission from AGN provides us with unprecedented insights into the physics of extragalactic jets. The emission from these jets fits naturally into the existing theoretical framework of relativistic jets as inferred from parsec scale and kiloparsec scale observations. Models of the γ-ray fluxes give us important knowledge of jet parameters, in particular magnetic fields and the size of...

The amplitude of jet distortions and accompanying pressure and velocity fluctuations resulting from Kelvin-Helmholtz instability of three dimensional relativistic jets are explored. The effect of instability on jets as they accelerate from subto super-Alfvénic speeds is explored and a relativistic stabilization mechanism for trans-Alfvénic jets is proposed. The level to which asymmetric instabi...

We present an analysis of OH, CN, and C2 jets observed in the coma of Comet Hale– Bopp on UT April 22, 23, and 25, 1997. Monte Carlo models designed to simulate the gas jets were employed to analyze the nuclear active areas responsible for the observed coma gas jets. Our results indicate that four active areas are necessary to reproduce the CN and C2 jets while five active areas are required to...

We present multi-dimensional simulations of magnetized radiative jets appropriate to Young Stellar Objects. Magnetized jets subject to collisionally excited radiative losses have not, as yet, received extensive scrutiny. The purpose of this letter is to articulate the propagation dynamics of radiative MHD jets in the context of the extensive jet literature. Most importantly, we look for morphol...

abstract in the present article, effective parameters of the buoyant jets have been evaluated in the stagnant ambient fluid. the jet parameters, geometry parameters and environmental parameters are investigated. using dimensional analysis, a set of dimensionless functions was obtained. to achieve the exact functions, a physical model was built in the hydraulic laboratory of shahid chamran unive...

This paper presents a new event generator, ALPGEN, dedicated to the study of multiparton hard processes in hadronic collisions. The code performs, at the leading order in QCD and EW interactions, the calculation of the exact matrix elements for a large set of parton-level processes of interest in the study of the Tevatron and LHC data. The current version of the code describes the following fin...

We study the bending of jets in binary stellar systems. A compact companion accretes mass from the slow wind of the mass-losing primary star, forms an accretion disk, and blows two opposite jets. These fast jets are bent by the slow wind. Disregarding the orbital motion, we find the dependence of the bending angle on the properties of the slow wind and the jets. Bending of jets is observed in p...

We present five epochs of simultaneous radio (VLA) and X-ray (Chandra) observations of SS 433, to study the relation between the radio and X-ray emission in the arcsecond-scale jets of the source. We detected X-ray emission from the extended jets in only one of the five epochs of observation, indicating that the X-ray reheating mechanism is transient. The reheating does not correlate with the t...