Orateur
Description
Gravitational-wave (GW) dark sirens statistically associate GW luminosity-distance measurements with galaxies consistent with the source localization. This association contains astrophysical information about how compact binaries populate galaxies and the likely hosts of individual events. To date, however, dark-siren analyses have focused primarily on cosmology, fixing the galaxy–merger relation and marginalizing over host identity. In this talk, I will instead discuss how dark-siren observations can be used as an astrophysical probe, and present an inference framework that jointly constrains the galaxy dependence of merger rates and yields the host probabilities of individual events. The framework provides a criterion for reducing the potential hosts of a well-localized, electromagnetically dark, event to a compact target list for electromagnetic follow-up, accounting for catalog incompleteness and galaxy-dependent merger probabilities. Applied blindly to GW170817, the method recovers NGC4993 as the highest-ranked host and constrains the galaxy luminosity weighting, with a mild preference for non-uniform host weights. These results illustrate how dark-siren analyses can provide information about the astrophysics of compact-binary mergers that lack an identified electromagnetic counterpart. Self-calibration of the galaxy-weighting prescription may also help reduce a potential source of systematic uncertainty in cosmological inference.
| Which working group does your abstract concern? | Cosmologie / Cosmology |
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