Timing observations of three Galactic millisecond pulsars. Issue 4 (2nd September 2021)

• Record Type: Journal Article
• Authors: Lorimer, D R; Kawash, A M; Freire, P C C; Smith, D A; Kerr, M; McLaughlin, M A; Mickaliger, M B; Spiewak, R; Bailes, M; Barr, E; Burgay, M; Cameron, A D; Camilo, F; Johnston, S; Jankowski, F; Keane, E F; Keith, M; Kramer, M; Possenti, A
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 507:Issue 4(2021)
• Page Start: 5303
• Page End: 5309
• Publication Date: 2021-09-02
• Subjects: pulsars: individual (PSR J0921–5202, PSR J1146–6610, PSR J1546–5925) -- stars: neutron; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab2474
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We report observed and derived timing parameters for three millisecond pulsars (MSPs) from observations collected with the Parkes 64-m telescope, Murriyang . The pulsars were found during reprocessing of archival survey data by Mickaliger et al. One of the new pulsars (PSR J1546–5925) has a spin period P = 7.8 ms and is isolated. The other two (PSR J0921–5202 with P = 9.7 ms and PSR J1146–6610 with P = 3.7 ms) are in binary systems around low-mass (${\gt}0.2\, {\rm M}_{\odot }$ ) companions. Their respective orbital periods are 38.2 and 62.8 d. While PSR J0921–5202 has a low orbital eccentricity e = 1.3 × 10 −5, in keeping with many other Galactic MSPs, PSR J1146–6610 has a significantly larger eccentricity, e = 7.4 × 10 −3 . This makes it a likely member of a group of eccentric MSP–helium white dwarf binary systems in the Galactic disc whose formation is poorly understood. Two of the pulsars are co-located with previously unidentified point sources discovered with the Fermi satellite's Large Area Telescope, but no γ-ray pulsations have been detected, likely due to their low spin-down powers. We also show that, particularly in terms of orbital diversity, the current sample of MSPs is far from complete and is subject to a number of selection biases.