DISCOVERY OF A MILLISECOND PULSAR IN THE 5.4 DAY BINARY 3FGL J1417.5-4402: OBSERVING THE LATE PHASE OF PULSAR RECYCLING

作者：Camilo F^*; Reynolds J E; Ransom S M; Halpern J P; Bogdanov S; Kerr M; Ray P S; Cordes J M; Sarkissian J; Barr E D; Ferrara E C

来源：Astrophysical Journal, 2016, 820(1): 6.

DOI：10.3847/0004-637X/820/1/6

• pulsars: individual (PSR J1417-4402)

In a search of the unidentified Fermi gamma-ray source 3FGL. J1417.5-4402 with the Parkes radio telescope, we discovered PSR. J1417-4402, a 2.66 ms pulsar having the same 5.4 day orbital period as the optical and X-ray binary identified by Strader et al. The existence of radio pulsations implies that the neutron star is currently not accreting. Substantial outflows from the companion render the radio pulsar undetectable for more than half of the orbit, and may contribute to the observed H alpha emission. Our initial pulsar observations, together with the optically inferred orbit and inclination, imply a mass ratio of 0.171 +/- 0.002, a companion mass of M-2 = 0.33 +/- 0.03 M-circle dot, and a neutron star mass in the range 1.77 <= M-1 <= 2.13 M-circle dot. However, there remains a discrepancy between the distance of 4.4 kpc inferred from the optical properties of the companion and the smaller radio dispersion measure distance of 1.6 kpc. The smaller distance would reduce the inferred Roche-lobe filling factor, increase the inferred inclination angle, and decrease the masses. As a wide binary, PSR. J1417-4402 differs from the radio-eclipsing black widow and redback pulsars being discovered in large numbers by Fermi. It is probably a system that began mass transfer onto the neutron star after the companion star left the main sequence. The companion should end its evolution as a He white dwarf in a 6-20 day orbit, i.e., as a typical binary millisecond pulsar companion.

• 出版日期2016-3-20