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Competition of spatial and temporal instabilities under time delay near codimension-two Turing-Hopf bifurcations
Competition of spatial and temporal instabilities under time delay near the
codimension-two Turing-Hopf bifurcations is studied in a reaction-diffusion
equation. The time delay changes remarkably the oscillation frequency, the
intrinsic wave vector, and the intensities of both Turing and Hopf modes. The
application of appropriate time delay can control the competition between the
Turing and Hopf modes. Analysis shows that individual or both feedbacks can
realize the control of the transformation between the Turing and Hopf patterns.
Two dimensional numerical simulations validate the analytical results.Comment: 13 pages, 6 figure
The diffuse gamma-ray emission toward the Galactic mini starburst W43
In this paper we report the Fermi Large Area Telescope (LAT) detection of the
gamma-ray emission toward the young star forming region W43. Using the latest
source catalog and diffuse background models, the extended gamma-ray excess is
detected with a significance of about 16 . The gamma-ray emission has a
spectrum with a photon index of . We also performed a detailed
analysis of the gas content in this region by taking into account the opacity
correction to the HI gas column density. The total cosmic-ray (CR) proton
energy is estimated to be on the order of assuming the
gamma-ray are produced from the interaction of the accelerated protons and
nuclei with the ambient gas. Comparing this region to the other star formation
regions in our Galaxy, we find that the CR luminosity is better correlated with
the wind power than the star formation rate (SFR). This result suggests that
CRs are primarily accelerated by stellar wind in these systemsComment: accepted for publications in A&
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