PSR J1518+4904: A Mildly Relativistic Binary Pulsar System
Abstract
PSR J1518+4904 is a recently discovered 40.9~ms pulsar in an 8.6 day, moderately eccentric orbit. We have measured pulse arrival times for this pulsar over 1.4~yr at several radio frequencies, from which we have derived high precision rotational, astrometric, and orbital parameters. The upper limit for the period derivative of the pulsar, dP/dt<4x10^-20, gives a characteristic age of at least 1.6x10^10 yr, among the highest known. We find the orbit to be precessing at a rate of 0.0111+-0.0002 yr^-1, which yields a total system mass (pulsar plus companion) of 2.62+-0.07 M_solar according to general relativity. Further analysis of the orbital parameters yields a firm upper limit of 1.75 M_solar on the pulsar mass and constrains the companion mass to the range 0.9 to 2.7 M_solar. These masses, together with the sizable orbital eccentricity and other evidence, strongly suggest that the companion is a second neutron star.
Keywords
Cite
@article{arxiv.astro-ph/9605122,
title = {PSR J1518+4904: A Mildly Relativistic Binary Pulsar System},
author = {D. J. Nice and R. W. Sayer and J. H. Taylor},
journal= {arXiv preprint arXiv:astro-ph/9605122},
year = {2009}
}
Comments
12 pages (including figures), AASTeX. To Appear in the Astrophysical Journal (Letters)