Abstract
Globular clusters (GCs) are particularly efficient at forming millisecond pulsars. Among these pulsars, about half lack a companion star, a significantly higher fraction than in the Galactic field. This fraction increases further in some of the densest GCs, especially those that have undergone core collapse, suggesting that dynamical interaction processes play a key role. For the first time, we create N-body models that reproduce the ratio of single-to-binary pulsars in Milky Way-like GCs. We focus especially on NGC 6752, a typical core-collapsed cluster with many observed millisecond pulsars. Previous studies suggested that an increased rate of neutron star binary disruption in the densest clusters could explain the overabundance of single pulsars in these systems. Here, we demonstrate that binary disruption is ineffective and instead we propose that two additional dynamical processes play dominant roles: (1) tidal disruption of main-sequence stars by neutron stars and (2) gravitational collapse of heavy white dwarf binary merger remnants. Neutron stars formed through these processes may also be associated with fast radio bursts similar to those observed recently in an extragalactic GC.
| Original language | English (US) |
|---|---|
| Article number | 98 |
| Journal | Astrophysical Journal |
| Volume | 961 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2024 |
Funding
We thank Chris Thompson and Ue-Li Pen for helpful discussions, and the anonymous referee for helpful comments and suggestions. C.S.Y. acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC) DIS-2022-568580. Support for K.K. was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51510 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. S.M.R. is a CIFAR Fellow and is supported by the NSF Physics Frontiers Center award 2020265. F.A.R. acknowledges support from NSF grant AST-2108624 and NASA ATP grant 80NSSC22K0722. This research was supported in part through the computational resources and staff contributions provided for the Quest high-performance computing facility at Northwestern University, which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology. This work was performed in part at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-2210452, and was partially supported by a grant from the Simons Foundation. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science