Algorithmic Pulsar Timer for Binaries

Pulsar timing is a powerful tool that, by accounting for every rotation of a pulsar, precisely measures the spin frequency, spin frequency derivatives, astrometric position, binary parameters when applicable, properties of the interstellar medium, and potentially general relativistic effects. Typically, this process demands fairly stringent scheduling requirements for monitoring observations as well as deep domain knowledge to “phase connect” the timing data. We present an algorithm that automates the pulsar-timing process for binary pulsars, whose timing solutions have an additional level of complexity, although the algorithm works for isolated pulsars as well. Using the statistical F-test and the quadratic dependence of the reduced χ 2 near a minimum, the global rotation count of a pulsar can be determined efficiently and systematically. We have used our algorithm to establish timing solutions for two newly discovered binary pulsars, PSRs J1748−2446aq and J1748−2446at, in the globular cluster Terzan 5, using ∼70 Green Bank Telescope observations from the last 13 yr

Missing for 20 yr: MeerKAT Redetects the Elusive Binary Pulsar M30B

PSR J2140−2311B is a 13 ms pulsar discovered in 2001 in a 7.8 hr Green Bank Telescope observation of the core-collapsed globular cluster M30 and predicted to be in a highly eccentric binary orbit. This pulsar has eluded detection since then; therefore, its precise orbital parameters have remained a mystery until now. In this work, we present the confirmation of this pulsar using observations taken with the UHF receivers of the MeerKAT telescope as part of the TRAPUM Large Survey Project. Taking advantage of the beamforming capability of our backends, we have localized it, placing it 1.′2(1) from the cluster center. Our observations have enabled the determination of its orbit: It is highly eccentric (e = 0.879) with an orbital period of 6.2 days. We also measured the rate of periastron advance, ω ̇ = 0.078 ± 0.002 deg yr − 1 . Assuming that this effect is fully relativistic, general relativity provides an estimate of the total mass of the system, M TOT = 2.53 ± 0.08 M ⊙, consistent with the lightest double neutron star systems known. Combining this with the mass function of the system gives the pulsar and companion masses of m p 1.10 M ⊙, respectively. The massive, undetected companion could either be a massive white dwarf or a neutron star. M30B likely formed as a result of a secondary exchange encounter. Future timing observations will allow the determination of a phase-coherent timing solution, vastly improving our uncertainty in ω ̇ and likely enabling the detection of additional relativistic effects, which will determine m p and m

Algorithmic Pulsar Timer for Binaries

Pulsar timing is a powerful tool that, by accounting for every rotation of a pulsar, precisely measures the spin frequency, spin frequency derivatives, astrometric position, binary parameters when applicable, properties of the interstellar medium, and potentially general relativistic effects. Typically, this process demands fairly stringent scheduling requirements for monitoring observations as well as deep domain knowledge to “phase connect” the timing data. We present an algorithm that automates the pulsar-timing process for binary pulsars, whose timing solutions have an additional level of complexity, although the algorithm works for isolated pulsars as well. Using the statistical F -test and the quadratic dependence of the reduced χ ^2 near a minimum, the global rotation count of a pulsar can be determined efficiently and systematically. We have used our algorithm to establish timing solutions for two newly discovered binary pulsars, PSRs J1748−2446aq and J1748−2446at, in the globular cluster Terzan 5, using ∼70 Green Bank Telescope observations from the last 13 yr

Missing for 20 yr: MeerKAT Redetects the Elusive Binary Pulsar M30B

PSR J2140−2311B is a 13 ms pulsar discovered in 2001 in a 7.8 hr Green Bank Telescope observation of the core-collapsed globular cluster M30 and predicted to be in a highly eccentric binary orbit. This pulsar has eluded detection since then; therefore, its precise orbital parameters have remained a mystery until now. In this work, we present the confirmation of this pulsar using observations taken with the UHF receivers of the MeerKAT telescope as part of the TRAPUM Large Survey Project. Taking advantage of the beamforming capability of our backends, we have localized it, placing it 1.′2(1) from the cluster center. Our observations have enabled the determination of its orbit: It is highly eccentric ( e = 0.879) with an orbital period of 6.2 days. We also measured the rate of periastron advance, $\dot{\omega }=0.078\pm 0.002\,\deg \,{\mathrm{yr}}^{-1}$ . Assuming that this effect is fully relativistic, general relativity provides an estimate of the total mass of the system, M _TOT = 2.53 ± 0.08 M _⊙ , consistent with the lightest double neutron star systems known. Combining this with the mass function of the system gives the pulsar and companion masses of m _p 1.10 M _⊙ , respectively. The massive, undetected companion could either be a massive white dwarf or a neutron star. M30B likely formed as a result of a secondary exchange encounter. Future timing observations will allow the determination of a phase-coherent timing solution, vastly improving our uncertainty in $\dot{\omega }$ and likely enabling the detection of additional relativistic effects, which will determine m _p and m _c