GBT21B-277

Long Term Timing of 64 Recycled Pulsars in Bulge Globular Clusters

Abstract

We propose to continue timing 64 (and still counting) recycled pulsars in the
bulge globular clusters Terzan 5, M28, NGC6440, NGC6652, and NGC6544 over the
next year using the coherent-filterbank mode of VEGAS at S-band. The majority
of these pulsars (54 of 64) were discovered with the GBT and many of them are
exotic or even unique pulsar systems. They include 39 binary pulsars, 14 of
which are in highly eccentric orbits and several of which appear to be massive
neutron stars. There are at least 8 eclipsing systems, all of which are
X-ray sources, one of which switches on as a LMXB (M28I), and one of which
contains the fastest rotating neutron star known. Our proposed observations,
totaling 75 hours and including high quality polarization measurements, will
extend and improve our timing solutions and allow new insights into pulsar
astronomy, neutron star physics, binary and globular cluster evolution, the
interstellar medium, the Galactic magnetic field, and globular cluster dynamics.

Investigators

Name	Institution
Scott Ransom *	National Radio Astronomy Observatory; Virginia, University of
Paulo Freire	Max-Planck-Institut für Radioastronomie
Ingrid Stairs	British Columbia, University of
Jason Hessels	Netherlands Institute for Radio Astronomy; Amsterdam, Universiteit van
Ryan Lynch	Green Bank Observatory
Megan DeCesar	George Mason University

* indicates the PI