36,225 research outputs found
Precision measurement with an optical Josephson junction
We study a new type of Josephson device, the so-called "optical Josephson
junction" as proposed in Phys. Rev. Lett. {\bf 95}, 170402 (2005). Two
condensates are optically coupled through a waveguide by a pair of Bragg beams.
This optical Josephson junction is analogous to the usual Josephson junction of
two condensates weakly coupled via tunneling. We discuss the use of this
optical Josephson junction, for making precision measurements.Comment: 6 pages, 1 figur
High-Energy emissions from the Pulsar/Be binary system PSR J2032+4127/MT91 213
PSR J2032+4127 is a radio-loud gamma-ray-emitting pulsar; it is orbiting
around a high-mass Be type star with a very long orbital period of 25-50years,
and is approaching periastron, which will occur in late 2017/early 2018. This
system comprises with a young pulsar and a Be type star, which is similar to
the so-called gamma-ray binary PSR~B1259-63/LS2883. It is expected therefore
that PSR J2032+4127 shows an enhancement of high-energy emission caused by the
interaction between the pulsar wind and Be wind/disk around periastron. Ho et
al. recently reported a rapid increase in the X-ray flux from this system. In
this paper, we also confirm a rapid increase in the X-ray flux along the orbit,
while the GeV flux shows no significant change. We discuss the high-energy
emissions from the shock caused by the pulsar wind and stellar wind interaction
and examine the properties of the pulsar wind in this binary system. We argue
that the rate of increase of the X-ray flux observed by Swift indicates (1) a
variation of the momentum ratio of the two-wind interaction region along the
orbit, or (2) an evolution of the magnetization parameter of the pulsar wind
with the radial distance from the pulsar. We also discuss the pulsar wind/Be
disk interaction at the periastron passage, and propose the possibility of
formation of an accretion disk around the pulsar. We model high-energy
emissions through the inverse-Compton scattering process of the
cold-relativistic pulsar wind off soft photons from the accretion disk.Comment: 18 pages, 23 figures, 1 Table, accepted for publication in Ap
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