47,493 research outputs found
Clues to the origin of Fermi Bubbles from OVIII/OVII line ratio
We constrain the origin of Fermi Bubbles using 2D hydrodynamical simulations
of both star formation driven and black hole accretion driven wind models. We
compare our results with recent observations of OVIII to OVII line ratio within
and near Fermi Bubbles. Our results suggest that independent of the driving
mechanisms, a low luminosity ( erg
s) energy injection best reproduces the observed line ratio for which
the shock temperature is K. Assuming the Galactic halo
temperature to be K, we estimate the shock velocity to be km s for a weak shock. The corresponding estimated age of the Fermi
bubbles is Myr. Such an event can be produced either by a star
formation rate of M yr at the Galactic centre or a
very low luminosity jet/accretion wind arising from the central black hole. Our
analysis rules out any activity that generates an average mechanical luminosity
\ergps as a possible origin of the Fermi Bubbles.Comment: 14 pages, 9 figures, accepted version (MNRAS); includes updates on
the electron-proton equilibrium time scale and its implications for high
energy jet
Quark-lepton complementarity model based predictions for with neutrino mass hierarchy
After the successful investigation and confirmation of non zero
by various experiments, we are standing at a square where
we still encounter a number of issues, which are to be settled. In this paper,
we have extended our recent work towards a precise prediction of the
mixing angle, taking into account the neutrino mass
hierarchy. We parameterize the non-trivial correlation between quark (CKM) and
lepton (PMNS) mixing matrices in quark-lepton complementarity (QLC) model as
, where is a diagonal phase matrix.
Monte Carlo simulations are used to estimate the texture of and compare
the results with the standard Tri-Bi-Maximal (TBM) and Bi-Maximal(BM)
structures of neutrino mixing matrix. We have predicted the value of
for normal and inverted neutrino mass hierarchies. The
value of obtained for two cases are about away
from each other, implying the better precision can give us a strong hint for
the type of neutrino mass hierarchy.Comment: 3 pages, 3 figure
Bound State Solutions of Klein-Gordon Equation with the Kratzer Potential
The relativistic problem of spinless particle subject to a Kratzer potential
is analyzed. Bound state solutions for the s-wave are found by separating the
Klein-Gordon equation in two parts, unlike the similar works in the literature,
which provides one to see explicitly the relativistic contributions, if any, to
the solution in the non-relativistic limit.Comment: 6 page
Double-diffusive Convection in Compressible Walters' B' Elastico-viscous Fluid in Hydromagnetics
On-site residence time in a driven diffusive system: violation and recovery of mean-field
We investigate simple one-dimensional driven diffusive systems with open
boundaries. We are interested in the average on-site residence time defined as
the time a particle spends on a given site before moving on to the next site.
Using mean-field theory, we obtain an analytical expression for the on-site
residence times. By comparing the analytic predictions with numerics, we
demonstrate that the mean-field significantly underestimates the residence time
due to the neglect of time correlations in the local density of particles. The
temporal correlations are particularly long-lived near the average shock
position, where the density changes abruptly from low to high. By using Domain
wall theory (DWT), we obtain highly accurate estimates of the residence time
for different boundary conditions. We apply our analytical approach to
residence times in a totally asymmetric exclusion process (TASEP), TASEP
coupled to Langmuir kinetics (TASEP + LK), and TASEP coupled to mutually
interactive LK (TASEP + MILK). The high accuracy of our predictions is verified
by comparing these with detailed Monte Carlo simulations
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