The Contribution of Disrupted Dense Star Clusters to Gaia’s Compact Object Binaries
4 affiliations
- 1University of Toronto
- 2McMaster University
- 3Universidade de Santiago de Compostela
- 4California Institute of Technology
Abstract
We present the first model of the Milky Way’s detectable compact object–luminous star binary population from disrupted dense star clusters. We bridge large-scale cosmological star cluster formation with high-resolution dynamical evolution of compact object binaries by mapping the predicted star clusters from the EMP- Pathfinder simulations to N -body Cluster Monte Carlo models. We predict that approximately 3 × 10 ⁵ white dwarfs (WDs), 1.5 × 10 ⁵ black holes (BHs), and 1 × 10 ³ neutron stars (NSs) in binaries with luminous companions are released to the Galaxy from now-disrupted dense star clusters throughout the history of the Milky Way. Synthetic observations modeled with the gaiamock pipeline reveal that the modeled Gaia DR3 yields are sparse (≈2 WDs, 0 NS, 0 BHs at 90% credibility), with the majority lying beyond the detection horizon. Gaia DR4 is expected to increase the observational yield of these systems only marginally, as the benefits of an expanded search volume are largely offset by the diminished astrometric and photometric precision of more distant sources (≈14 WDs, 0 NS, 0 BHs). While the underlying BH binary population is similar to that of WDs, they are detected far less frequently; they tend to pair with lower-mass, dimmer companions and have less temporal coverage of their long orbital periods. For NSs, we suggest that the observed overrepresentation of metal-poor, halo systems is inconsistent with an origin in disrupted dense star clusters. Instead, the observed Gaia NS population could reflect the accretion history of metal-poor, dwarf galaxies into the Milky Way, isolated binary star evolution, or supernova physics.
Related
- The Ejection and Detectability of High- and Hypervelocity Stars by Compact Object Binaries in Globular Clusters
- Hunting for Compact Object Binaries from eRASS1 Optical Counterparts through ZTF Time-domain Photometry and Multi-wavelength Surveys
- Hunting for Compact Object Binaries from eRASS1 Optical Counterparts through ZTF Time-domain Photometry and Multiwavelength Surveys
- A Sample of Long-Period Binaries with Dormant Compact-Object Candidates from LAMOST DR13 MRS and Gaia DR3
- A Sample of Long-period Binaries with Dormant Compact-object Candidates from LAMOST DR13 MRS and Gaia DR3
BibTeX
@article{schiebelbeinzwack2026contribution,
title = {{The Contribution of Disrupted Dense Star Clusters to Gaia’s Compact Object Binaries}},
author = {Aryanna Schiebelbein-Zwack and Claire S. Ye and Marta Reina-Campos and Aeysha Munawwarah and Kareem El-Badry and Pranav Nagarajan},
journal = {The Astrophysical Journal},
year = {2026},
month = nov,
doi = {10.3847/1538-4357/aeb303},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aeb303},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The Contribution of Disrupted Dense Star Clusters to Gaia’s Compact Object Binaries
AU - Aryanna Schiebelbein-Zwack
AU - Claire S. Ye
AU - Marta Reina-Campos
AU - Aeysha Munawwarah
AU - Kareem El-Badry
AU - Pranav Nagarajan
PY - 2026
DA - 2026/11/02
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aeb303
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aeb303
AB - We present the first model of the Milky Way’s detectable compact object–luminous star binary population from disrupted dense star clusters. We bridge large-scale cosmological star cluster formation with high-resolution dynamical evolution of compact object binaries by mapping the predicted star clusters from the EMP- Pathfinder simulations to N -body Cluster Monte Carlo models. We predict that approximately 3 × 10 ⁵ white dwarfs (WDs), 1.5 × 10 ⁵ black holes (BHs), and 1 × 10 ³ neutron stars (NSs) in binaries with luminous companions are released to the Galaxy from now-disrupted dense star clusters throughout the history of the Milky Way. Synthetic observations modeled with the gaiamock pipeline reveal that the modeled Gaia DR3 yields are sparse (≈2 WDs, 0 NS, 0 BHs at 90% credibility), with the majority lying beyond the detection horizon. Gaia DR4 is expected to increase the observational yield of these systems only marginally, as the benefits of an expanded search volume are largely offset by the diminished astrometric and photometric precision of more distant sources (≈14 WDs, 0 NS, 0 BHs). While the underlying BH binary population is similar to that of WDs, they are detected far less frequently; they tend to pair with lower-mass, dimmer companions and have less temporal coverage of their long orbital periods. For NSs, we suggest that the observed overrepresentation of metal-poor, halo systems is inconsistent with an origin in disrupted dense star clusters. Instead, the observed Gaia NS population could reflect the accretion history of metal-poor, dwarf galaxies into the Milky Way, isolated binary star evolution, or supernova physics.
SN - 1538-4357
SN - 0004-637X
ER -