The mass of the neutron star in the binary millisecond pulsar PSR J1012+5307

Thumbnail Image
3899.pdf(477.93 KB)
Published Version
Callanan, Paul J.
Garnavich, Peter M.
Koester, D.
Journal Title
Journal ISSN
Volume Title
Oxford University Press
Research Projects
Organizational Units
Journal Issue
We have measured the radial velocity variation of the white dwarf secondary in the binary system containing the millisecond pulsar PSR J1012 + 5307. Combined with the orbital parameters of the radio pulsar, we infer a mass ratio q (=M-1/M-2) = 10.5 +/- 0.5 OUT optical spectroscopy has also allowed us to determine the mass of the white dwarf companion by fitting the spectrum to a grid of DA model atmospheres: we estimate M-2 = 0.16 +/- 0.02 M., and hence the mass of the neutron star is 1.64 +/- 0.22 M., where the error is dominated by that of M-2. The orbital inclination is 52 +/- 4 deg. For an initial neutron star mass of similar to 1.4 M., only a few tenths of a solar mass at most has been successfully accreted over the lifetime of the progenitor low-mass X-ray binary. If the initial mass of the secondary was similar to 1 M., our result suggests that the mass transfer may have been non-conservative.
Stars , Binaries , General , Neutron , Pulsars , Individual , PSR J1012 + 5307
Callanan, P. J., Garnavich, P. M. and Koester, D. (1998) 'The mass of the neutron star in the binary millisecond pulsar PSR J1012 + 5307', Monthly Notices of the Royal Astronomical Society, 298(1), pp. 207-211. doi: 10.1046/j.1365-8711.1998.01634.x
© 1998, Royal Astronomical Society