4,781 research outputs found
Fermi Variability Study of the Candidate Pulsar Binary 2FGL~J0523.3-2530
The Fermi source 2FGL~J0523.32530 has recently been identified as a
candidate millisecond pulsar binary with an orbital period of 16.5 hrs. We have
carried out detailed studies of the source's emission properties by analyzing
data taken with the Fermi Large Area Telescope in the 0.2--300 GeV energy
range. Long-term, yearly variability from the source has been found, with a
factor of 4 flux variations in 1--300 GeV. From spectral analysis, we find an
extra spectral component at 2--3 GeV that causes the source brightening. While
no orbital modulations have been found from the Fermi data over the whole
period of 2008--2014, orbital modulation in the source's 2 GeV emission is
detected during the last 1.5 yrs of the Fermi observation. Our results support
the millisecond pulsar binary nature of 2FGL~J0523.32530. Multi-wavelength
observations of the source are warranted in order to find any correlated flux
variations and thus help determine the origin of the long-term variability,
which currently is not understood.Comment: 8 pages, 5 figures, comments from Referee were incorporated, accepted
for publication in Ap
Possibility of S=1 spin liquids with fermionic spinons on triangular lattices
In this paper we generalize the fermionic representation for spins to
arbitrary spins. Within a mean field theory we obtain several spin liquid
states for spin antiferromagnets on triangular lattices, including
gapless f-wave spin liquid and topologically nontrivial spin liquid.
After considering different competing orders, we construct a phase diagram for
the -- model. The application to recently discovered material
is discussed.Comment: 5 pages, 3 figure
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