http://arxiv.org/abs/1402.6401
We report the results from our analysis of the Fermi Large Area Telescope data of the Fermi unassociated source 2FGL J1906.5+0720, which is a high-ranked candidate pulsar. We first update the ephemeris for PSR J1907+0602, which is used to remove any possible contamination due to strong emission from this nearby pulsar. A small glitch $\Delta\nu/\nu \simeq 1.5 \times$ 10$^{-9}$ is found around MJD 55866 in the pulsar. From our analysis, 2FGL J1906.5+0720 is confirmed to have a significant low energy cutoff at ~1 GeV in its emission (14$\sigma$–18$\sigma$ significance), consistent with those seen in young pulsars. We search for pulsations but no spin frequency signals are found in a frequency range of 0.5–32 Hz. No single model can fully describe the source’s overall Fermi gamma-ray spectrum, and the reason for this is because of excess emission detected at energies of >4 GeV. The high-energy component, also seen in the Crab pulsar and several gamma-ray binaries and probably due to a cold pulsar wind, likely originates from 2FGL J1906.5+0720 as either contamination from nearby sources or existence of an extended source is excluded. We conclude that 2FGL J1906.5+0720 is likely a pulsar based on the emission properties, and radio search for pulsations is needed in order to confirm its pulsar nature.
Y. Xing and Z. Wang
Thu, 27 Feb 14
59/59
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