Speaker
Joeri van Leeuwen
(ASTRON / U. Amsterdam)
Description
PSR J1906+0746 is a young pulsar in the relativistic binary with the second-shortest known orbit, of 3.98 hours. We will present a timing study based on five years of observations, conducted with the 5 largest radio telescopes in the world, aimed at determining the companion nature (van Leeuwen et al. 2015). Through the measurement of three post-Keplerian orbital parameters we find the pulsar and companion masses to be 1.323(11)M⊙ and 1.290(11)M⊙ respectively. These masses are compatible with a neutron star companion, but also fit well in the known mass distribution of white dwarfs around young pulsars such as J1906+0746. Neither radio pulsations nor any
dispersion-inducing outflows that could have established the companion nature were detected. We derive an HI-absorption distance, which indicates an optical confirmation of a white dwarf companion is very challenging. The pulsar is fading fast due to geodetic precession, limiting future timing improvements. We conclude that young pulsar J1906+0746 is either part of a binary neutron star, or is orbited by an older white dwarf, in an exotic system formed through two stages of mass transfer.
Author
Joeri van Leeuwen
(ASTRON / U. Amsterdam)
Co-author
Ingrid Stairs
(UBC)
