Timing of Five PALFA-Discovered Millisecond Pulsars

TL;DR

This paper reports the discovery and detailed timing analysis of five millisecond pulsars from the PALFA survey, highlighting their binary nature, potential redback classification, and their significance in understanding distant MSP populations.

Contribution

The paper presents five newly discovered MSPs with comprehensive timing data, including the first potential redback MSP from the PALFA survey, expanding the known population of distant, highly dispersed MSPs.

Findings

Four of the five MSPs are in low-eccentricity binary systems.

One MSP, PSR J1957+2516, is likely a redback with eclipses.

All five MSPs are distant (>3.1 kpc) and do not show gamma-ray pulsations.

Abstract

We report the discovery and timing results for five millisecond pulsars (MSPs) from the Arecibo PALFA survey: PSRs J1906+0055, J1914+0659, J1933+1726, J1938+2516, and J1957+2516. Timing observations of the 5 pulsars were conducted with the Arecibo and Lovell telescopes for time spans ranging from 1.5 to 3.3 yr. All of the MSPs except one (PSR J1914+0659) are in binary systems with low eccentricities. PSR J1957+2516 is likely a redback pulsar, with a ~0.1 $M_\odot$ companion and possible eclipses that last ~10% of the orbit. The position of PSR J1957+2516 is also coincident with a NIR source. All 5 MSPs are distant (>3.1 kpc) as determined from their dispersion measures, and none of them show evidence of $\gamma$-ray pulsations in a search of Fermi Gamma-Ray Space Telescope data. These 5 MSPs bring the total number of MSPs discovered by the PALFA survey to 26 and further demonstrate the power of this survey in finding distant, highly dispersed MSPs deep in the Galactic plane.