Open AccessPSR J1518+4904: A Mildly Relativistic Binary Pulsar System
Author(s) -
D. J. Nice,
R. W. Sayer,
J. H. Taylor
Publication year - 1996
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/310178
Subject(s) - pulsar , physics , neutron star , astrophysics , binary pulsar , orbital period , eccentricity (behavior) , orbit (dynamics) , orbital elements , orbital eccentricity , astronomy , general relativity , x ray pulsar , millisecond pulsar , planet , mathematical physics , stars , engineering , political science , law , aerospace engineering
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 thispulsar over 1.4~yr at several radio frequencies, from which we have derivedhigh precision rotational, astrometric, and orbital parameters. The upper limitfor the period derivative of the pulsar, dP/dt<4x10^-20, gives a characteristicage of at least 1.6x10^10 yr, among the highest known. We find the orbit to beprecessing 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 1.75M_solar on the pulsar mass and constrains the companion mass to the range 0.9to 2.7 M_solar. These masses, together with the sizable orbital eccentricityand other evidence, strongly suggest that the companion is a second neutronstar.Comment: 12 pages (including figures), AASTeX. To Appear in the Astrophysical Journal (Letters
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