25,365 research outputs found
An Imaging and Spectral Study of Ten X-Ray Filaments around the Galactic Center
We report the detection of 10 new X-ray filaments using the data from the
{\sl Chandra} X-ray satellite for the inner ( parsec)
around the Galactic center (GC). All these X-ray filaments are characterized by
non-thermal energy spectra, and most of them have point-like features at their
heads that point inward. Fitted with the simple absorbed power-law model, the
measured X-ray flux from an individual filament in the 2-10 keV band is to ergs cm s and the
absorption-corrected X-ray luminosity is ergs s
at a presumed distance of 8 kpc to the GC. We speculate the origin(s) of these
filaments by morphologies and by comparing their X-ray images with the
corresponding radio and infrared images. On the basis of combined information
available, we suspect that these X-ray filaments might be pulsar wind nebulae
(PWNe) associated with pulsars of age yr. The fact
that most of the filament tails point outward may further suggest a high
velocity wind blowing away form the GC.Comment: 29 pages with 7 figures and 3 pages included. Accepted to Ap
Generation of frequency multiplexed entangled single photons assisted by the entanglement
We present a scheme to generate the frequency multiplexed entangled (FME)
single photons based on the entanglement between two species atomic mixture
ensemble. The write and reads fields driven according to a certain timing
sequence, the generation of FME single photons can be repeated until success is
achieved. The source might have significant applications in wavelength division
multiplexing quantum key distribution.Comment: 4 pages, 4 figures, submitted to PR
Steady Bell state generation via magnon-photon coupling
We show that parity-time () symmetry can be spontaneously
broken in the recently reported energy level attraction of magnons and cavity
photons. In the -broken phase, magnon and photon form a
high-fidelity Bell state with maximum entanglement. This entanglement is steady
and robust against the perturbation of environment, in contrast to the general
wisdom that expects instability of the hybridized state when the symmetry is
broken. This anomaly is further understood by the compete of non-Hermitian
evolution and particle number conservation of the hybridized system. As a
comparison, neither -symmetry broken nor steady magnon-photon
entanglement is observed inside the normal level repulsion case. Our results
may open a novel window to utilize magnon-photon entanglement as a resource for
quantum technologies.Comment: 5 pages, 4 figure
H-Dihyperon in Quark Cluster Model
The H dihyperon (DH) is studied in the framework of the SU(3) chiral quark
model. It is shown that except the chiral field, the overall effect of
the other SU(3) chiral fields is destructive in forming a stable DH. The
resultant mass of DH in a three coupled channel calculation is ranged from 2225
to 2234 .Comment: 9 pages, emte
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