PSR~J1618−3921 is an 11.99-ms pulsar in a 22.7-d orbit around a likely low-mass He white dwarf companion, discovered in a survey of the intermediate Galactic latitudes at 1400 MHz conducted with the Parkes radio telescope in the late 1990s. Although PSR~J1618−3921 was discovered more than 15 years ago, only limited information has been published about this pulsar which has a surprisingly large orbital eccentricity (e≃0.027), considering its high spin frequency and likely small companion mass. The focus of this work is a precise measurement of the spin, astrometric and orbital characteristics of PSR J1618−3921. This was done with timing observations made at the Nan\c{c}ay Radio Telescope, from 2009 to 2017. We analyzed the timing data recorded at the Nan\c{c}ay Radio Telescope over several years to characterize the properties of PSR~J1618−3921. A rotation ephemeris for this pulsar was obtained by analyzing the times of arrival of the radio pulses at the telescope. We confirm the unusual eccentricity of PSR~J1618−3921 and discuss several hypotheses regarding its formation, in the context of other discoveries of recycled pulsars in eccentric orbits.
@article{arxiv.1801.07123,
title = {PSR J1618-3921: a recycled pulsar in an eccentric orbit},
author = {F. Octau and I. Cognard and L. Guillemot and T. M. Tauris and P. C. C. Freire and G. Desvignes and G. Theureau},
journal= {arXiv preprint arXiv:1801.07123},
year = {2018}
}
Comments
6 pages, 3 tables, 3 figures. Accepted for publication in Astronomy & Astrophysics