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Title: THE TIMING OF NINE GLOBULAR CLUSTER PULSARS

Journal Article · · Astrophysical Journal
 [1];  [2];  [3]
  1. Physics Department, McGill University, 3600 Rue University, Montreal, QC H3A 2T8 (Canada)
  2. Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)
  3. National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-4325 (United States)

We have used the Robert C. Byrd Green Bank Telescope to time nine previously known pulsars without published timing solutions in the globular clusters (GCs) M62, NGC 6544, and NGC 6624. We have full timing solutions that measure the spin, astrometric, and (where applicable) binary parameters for six of these pulsars. The remaining three pulsars (reported here for the first time) were not detected enough to establish solutions. We also report our timing solutions for five pulsars with previously published solutions, and find good agreement with other authors, except for PSR J1701-3006B in M62. Gas in this system is probably responsible for the discrepancy in orbital parameters, and we have been able to measure a change in the orbital period over the course of our observations. Among the pulsars with new solutions we find several binary pulsars with very low mass companions (members of the so-called 'black widow' class) and we are able to place constraints on the mass-to-light ratio in two clusters. We confirm that one of the pulsars in NGC 6624 is indeed a member of the rare class of non-recycled pulsars found in GCs. We have also measured the orbital precession and Shapiro delay for a relativistic binary in NGC 6544. If we assume that the orbital precession can be described entirely by general relativity, which is likely, we are able to measure the total system mass (2.57190(73) M{sub Sun }) and companion mass (1.2064(20) M{sub Sun }), from which we derive the orbital inclination (sin i = 0.9956(14)) and the pulsar mass (1.3655(21) M{sub Sun }), the most precise such measurement ever obtained for a millisecond pulsar. The companion is the most massive known around a fully recycled pulsar.

OSTI ID:
22011930
Journal Information:
Astrophysical Journal, Vol. 745, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English

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