A Multiwavelength Study of Nearby Millisecond Pulsar PSR J1400-1431: Improved Astrometry and an Optical Detection of Its Cool White Dwarf Companion
Abstract
In 2012, five high-school students involved in the Pulsar Search Collaboratory discovered the millisecond pulsar (MSP) PSR J1400-1431, and initial timing parameters were published in Rosen et al. a year later. Since then, we have obtained a phase-connected timing solution spanning five years, resolving a significant position discrepancy and measuring \dot{P}, proper motion, parallax, and a monotonic slope in dispersion measure over time. Due to PSR J1400-1431’s proximity and significant proper motion, we use the Shklovskii effect and other priors to determine a 95% confidence interval for PSR J1400-1431’s distance, d={270}-80+130 pc. With an improved timing position, we present the first detection of the pulsar’s low-mass white dwarf (WD) companion using the Goodman Spectrograph on the 4.1 m SOAR telescope. Deeper imaging suggests that it is a cool DA-type WD with {T}{eff}=3000+/- 100 K and R/{R}⊙ =(2.19+/- 0.03)× {10}-2 (d/270 {pc}). We show a convincing association between PSR J1400-1431 and a γ-ray point source, 3FGL J1400.5-1437, but only weak (3.3σ) evidence of pulsations after folding γ-ray photons using our radio timing model. We detect an X-ray counterpart with XMM-Newton, but the measured X-ray luminosity (1×1029 erg s-1) makes PSR J1400-1431 the least X-ray luminous rotation-powered MSP detected to date. Together, our findings present a consistent picture of a nearby (d≈ 230 pc) MSP in a 9.5-day orbit around a cool ∼0.3 M ⊙ WD companion, with orbital inclination I≳ 60^\circ .
- Publication:
-
The Astrophysical Journal
- Pub Date:
- September 2017
- DOI:
- 10.3847/1538-4357/aa8994
- arXiv:
- arXiv:1708.09386
- Bibcode:
- 2017ApJ...847...25S
- Keywords:
-
- binaries: general;
- pulsars: individual: J1400‑1431;
- stars: distances;
- white dwarfs;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 13 pages, 12 figures, 4 tables