The Black Widow millisecond pulsar is slowly vaporizing its companion star. Van Kerkwijk obtained spectra of the companion and measured how much its velocity changes during its orbit about 325 km/s. Because the star is illuminated by the pulsar the centre of light is closer to the centre of mass of the system than the centre of mass of the star does. With atmospheric modelling and modelling the light curve, the authors address this issue and the question of the orbital inclination, yielding a really heavy pulsar at 2.4 +/- 0.1 solar masses. Unfortunately once they account for the various systematic errors they get a quite modest and svelte neutron star whose mass is likely to be greater than 1.66 solar masses. The observations are exquisite; unfortunately the models are not yet up to providing strong constraints.
http://arxiv.org/abs/1009.5427 Evidence for a Massive Neutron Star from a Radial-Velocity Study of the Companion to the Black Widow Pulsar PSR B1957+20
3 comments:
Good luck to all those who watch over the course of this blog and congratulations for the content . It is very successful . Especially keep it up ! good luck
voyance gratuite par mail ; Voyance gratuite en ligne
I am continually searching online for ideas that can facilitate me. Thanks!
voyance par mail
It was a wonderful chance to visit this kind of site and I am happy to know. thank you so much for giving us a chance to have this opportunity! I will be back soon for updates.
voyance gratuite en ligne par mail
Post a Comment