The eccentric millisecond pulsar, PSR J0955$-$6150 I: Pulse profile analysis, mass measurements and constraints on binary evolution

Abstract

PSR J0955$-$6150 is a member of a class of eccentric MSP+He WD systems (eMSPs), whose binary evolution is poorly understood and believed to be different to that of traditional MSP+He WD systems. Measuring the masses of the stars in this system is important for testing hypotheses for the formation of eMSPs. We have carried out observations of this pulsar with the Parkes and MeerKAT radio telescopes. Our observations reveal a strong frequency evolution of this pulsar's intensity, with a spectral index ($\alpha$) of $-3.13(2)$. The sensitivity of MeerKAT has resulted in a $>10$-fold improvement in the timing precision compared to older Parkes observations. Combined with the 8-year timing baseline, it has allowed precise measurements of a proper motion and three orbital "post-Keplerian" parameters: the rate of advance of periastron, $\dot{\omega }=0.00152(1)\mathrm{deg}y{r}^{-1}$ and the orthometric Shapiro delay parameters, $h_3=0.89(7)\mu$s and $\varsigma =0.88(2)$. Assuming general relativity, we obtain $M_p=1.71(2)M_{\odot }$ for the mass of the pulsar and $M_c=0.254(2)M_{\odot }$ for the mass of the companion; the orbital inclination is 83.2(4) degrees. We find that the spin axis has a misalignment relative to the orbital angular momentum of $>4.8$ degrees at 99% CI. While the value of $M_{\mathrm{p}}$ falls within the wide range observed in eMSPs, $M_{\mathrm{c}}$ is significantly smaller than expected, allowing several formation hypotheses being ruled out. $M_{\mathrm{c}}$ is also significantly different from the expected value for an ideal low mass X-ray binary evolution scenario. The putative misalignment between the spin axis of the pulsar and the orbital angular momentum suggests that the unknown process that created the orbital eccentricity of the binary was also capable of changing its orbital orientation, an important evidence for understanding the origin of eMSPs.

20 pages, 9 figures, 5 tables, accepted for publication by the A&A

References in corpus (22)

• Array Programming with NumPy
• TEMPO2, a new pulsar timing package. I: Overview
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• PSRCHIVE and PSRFITS An Open Approach to Radio Pulsar Data Storage and Analysis
• Formation of Double Neutron Star Systems
• An Eccentric Binary Millisecond Pulsar in the Galactic Plane
• The MeerKAT Telescope as a Pulsar Facility: System verification and early science results from MeerTime
• Eight new millisecond pulsars from the first MeerKAT globular cluster census
• The MeerTime Pulsar Timing Array -- A Census of Emission Properties and Timing Potential
• An improved test of the strong equivalence principle with the pulsar in a triple star system
• Constraining particle acceleration in Sgr A* with simultaneous GRAVITY, Spitzer, NuSTAR and Chandra observations
• A Massive Millisecond Pulsar in an Eccentric Binary
• On the beam properties of radio pulsars with interpulse emission
• PSR J2222--0137. I. Improved physical parameters for the system
• On the formation of eccentric millisecond pulsars with helium white-dwarf companions
• The Relativistic Binary Programme on MeerKAT: Science objectives and first results
• The Thousand-Pulsar-Array programme on MeerKAT IV: Polarisation properties of young, energetic pulsars
• A Highly Eccentric 3.9-Millisecond Binary Pulsar in the Globular Cluster NGC 6652
• Magnetic angle evolution in accreting neutron stars
• Convection and rotation boosted prescription of magnetic braking: application to the formation of extremely low-mass white dwarfs
• Asymmetrical mass ejection from proto-white dwarfs and the formation of eccentric millisecond pulsar binaries
• Eccentric millisecond pulsars by resonant convection

Cited by in corpus (17)

• Maximum gravitational mass $M_{\mathrm{TOV}}=2.25_{-0.07}^{+0.08}{M}_{\odot }$ inferred at about $3\%$ precision with multimessenger data of neutron stars
• The MPIfR-MeerKAT Galactic Plane survey I -- System setup and early results
• Mass Distribution and Maximum Mass of Neutron Stars: Effects of Orbital Inclination Angle
• The birth mass function of neutron stars
• Possible binary neutron star merger history of the primary of GW230529
• Neutron star mass in dark matter clumps
• Direct nonparametric multimessenger constraints on the equation of state of cold dense nuclear matter
• Fastest spinning millisecond pulsars: indicators for quark matter in neutron stars?
• Impact of Asymmetrical Mass Ejection from Proto-White Dwarfs on the Properties of Binary Millisecond Pulsars
• White dwarf eccentricity fluctuation and dissipation by AGB convection
• Rapidly Spinning Massive Pulsars as an Indicator of Quark Deconfinement
• Topology of the Superconducting Heart of Neutron Stars: Effects of Microphysics and Gravitational-Wave Signatures
• Triple trouble with PSR J1618-3921: Mass measurements and orbital dynamics of an eccentric millisecond pulsar
• On the Formation of Eccentric Millisecond Pulsars by Accretion-induced Collapse of Massive White Dwarfs
• The spin-orbit alignment hypothesis in millisecond pulsars
• Compact binary system dynamics at the second post-Newtonian order: analytical formula of the coordinate time for eccentric and circular orbits
• Measuring black hole spin through gravitational lensing of pulsars