Physical drivers of host-galaxy dispersion measure

Characterize the physical drivers of the host-galaxy dispersion measure of fast radio bursts, including the relative contributions of halo gas, local environments, and galaxy-scale properties.

Background

The host-galaxy contribution to an FRB's observed dispersion measure is the least constrained component of the dispersion-measure budget. Studies disagree about whether it correlates with redshift, stellar mass, star-formation rate, or other host properties, partly because the host contribution is difficult to separate from the intergalactic contribution and possible intervening-halo contributions. Resolving these physical drivers is important for reliable redshift and cosmological inference.

References

A definitive understanding of the physical drivers of ${\rm DM_{host}$, whether they are halo gas, local environment, or galaxy‑scale properties, is still lacking.

— A Brief Review on the Statistical Properties of Fast Radio Bursts  (2609.25810 - Sang et al., 22 Sep 2026) in Section 2.1, Summary