Gravitational-wave dark sirens as astrophysical probes: inferring galaxy-merger relations and identifying individual hosts
Abstract
Gravitational-wave (GW) ``dark siren'' techniques, namely the statistical association of GW events with a galaxy catalog, have so far been used as a cosmological tool. Yet this association carries distinctive astrophysical information that remains unused---specifically, how compact binaries populate galaxies and the identities of individual hosts. In this work, we turn the dark-siren program into an astrophysical probe by inferring both simultaneously within a single hierarchical framework. The method reduces the many potential hosts to a compact, probabilistically ranked target list, providing a direct follow-up decision tool. Applied blindly to GW170817, it recovers NGC~4993 as the highest-ranked host and constrains the galaxy luminosity weighting, mildly favoring non-uniform host weights. Fixing the galaxy weighting can instead degrade host identification and even favor the wrong host. This framework recasts dark sirens as a potentially unique probe of the astrophysics of electromagnetically dark compact-binary mergers.
Related
- Inferring Properties of Rotating Core-Collapse Supernovae with Gravitational-Wave Detector Networks
- Gravitational Wave Diffractive Images Reveal the Structure of Astrophysical Objects
- Expanding the scope of dark siren cosmology: Inferring the population properties of gravitational wave-hosting galaxies
- Joint Fit of Galaxy Cluster Scaling Relations from Individual Weak Lensing Data: Comparison with Stacked Analysis and a Real Data Test
- GWTC-5.0: Methods for Identifying and Characterizing Gravitational-wave Transients
BibTeX
@misc{agapito2026gravitationalwave,
title = {{Gravitational-wave dark sirens as astrophysical probes: inferring galaxy-merger relations and identifying individual hosts}},
author = {Alessandro Agapito and Michele Mancarella},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.38110},
eprint = {2609.38110},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05784526v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Gravitational-wave dark sirens as astrophysical probes: inferring galaxy-merger relations and identifying individual hosts
AU - Alessandro Agapito
AU - Michele Mancarella
PY - 2026
DA - 2026/09/29
PB - HAL
DO - 10.48550/arxiv.2609.38110
UR - https://hal.science/hal-05784526v1
AB - Gravitational-wave (GW) ``dark siren'' techniques, namely the statistical association of GW events with a galaxy catalog, have so far been used as a cosmological tool. Yet this association carries distinctive astrophysical information that remains unused---specifically, how compact binaries populate galaxies and the identities of individual hosts. In this work, we turn the dark-siren program into an astrophysical probe by inferring both simultaneously within a single hierarchical framework. The method reduces the many potential hosts to a compact, probabilistically ranked target list, providing a direct follow-up decision tool. Applied blindly to GW170817, it recovers NGC~4993 as the highest-ranked host and constrains the galaxy luminosity weighting, mildly favoring non-uniform host weights. Fixing the galaxy weighting can instead degrade host identification and even favor the wrong host. This framework recasts dark sirens as a potentially unique probe of the astrophysics of electromagnetically dark compact-binary mergers.
ER -