59 research outputs found
A New Model For Vela Jr. Supernova Remnant
We consider Vela Jr. as being the old Supernova Remnant (SNR) at the
beginning of the transition from adiabatic to radiative stage of evolution.
According to our model, Vela Jr. is situated outside Vela SNR at the distance
of 600 pc and its age is 17500 yr. We model the high energy fluxes from Vela
Jr. and its broadband spectrum. We find our results compatible with
experimental data in radio waves, X- and gamma-rays. Our hydrodynamical model
of Vela Jr. explains the observed TeV gamma-ray flux by hadronic mechanism. The
proposed model does not contradict to the low density environment of the SNR
and does not need extreme fraction of the explosion energy to be transferred to
Cosmic Rays.Comment: Accepted for publication in Astroparticle Physic
The generation of low-energy cosmic rays in molecular clouds
It is argued that if cosmic rays penetrate into molecular clouds, the total
energy they lose can exceed the energy from galactic supernovae shocks. It is
shown that most likely galactic cosmic rays interacting with the surface layers
of molecular clouds are efficiently reflected and do not penetrate into the
cloud interior. Low-energy cosmic rays ( GeV) that provide the primary
ionization of the molecular cloud gas can be generated inside such clouds by
multiple shocks arising due to supersonic turbulence.Comment: 11 pages, no figure
Exact results on the dynamics of multi-component Bose-Einstein condensate
We study the time-evolution of the two dimensional multi-component
Bose-Einstein condensate in an external harmonic trap with arbitrary
time-dependent frequency. We show analytically that the time-evolution of the
total mean-square radius of the wave-packet is determined in terms of the same
solvable equation as in the case of a single-component condensate. The dynamics
of the total mean-square radius is also the same for the rotating as well as
the non-rotating multi-component condensate. We determine the criteria for the
collapse of the condensate at a finite time. Generalizing our previous work on
a single-component condensate, we show explosion-implosion duality in the
multi-component condensate.Comment: Two-column 6 pages, RevTeX, no figures(v1); Added an important
reference, version to appear in Physical Review A (v2
Laboratory Studies of Astrophysical Jets
Jets and outflows produced during star-formation are observed on many scales:
from the "micro-jets" extending a few hundred Astronomical Units to the
"super-jets" propagating to parsecs distances. Recently, a new "class" of
short-lived (hundreds of nano-seconds) centimetre-long jets has emerged in the
laboratory as a complementary tool to study these complex astrophysical flows.
Here I will discuss and review the recent work done on "simulating"
protostellar jets in the laboratory using z-pinch machines.Comment: 25 Pages, 11 Figures to appear in Lecture Notes in Physics. Series
Title: Jets from young stars IV: From models to observations and experiments
Editors: P. J. V. Garcia and J. M. T. Ferreira. Publisher: Springe
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