CHIME/FRB Catalog 1 results: statistical cross-correlations with large-scale structure

TL;DR

This paper reports the first statistical cross-correlation analysis between CHIME/FRB detected fast radio bursts and galaxy catalogs, revealing significant associations with large-scale structures and insights into FRB host environments.

Contribution

It presents the first evidence of angular cross-correlations between FRBs and galaxies, indicating some FRBs originate in the same dark matter halos as galaxies in specific redshift ranges.

Findings

Significant cross-correlation between FRBs and galaxies at z~0.3-0.5.

Evidence for a subset of FRBs with large host dispersion measures.

Large halos may host FRBs with high dispersion measures.

Abstract

The CHIME/FRB Project has recently released its first catalog of fast radio bursts (FRBs), containing 492 unique sources. We present results from angular cross-correlations of CHIME/FRB sources with galaxy catalogs. We find a statistically significant ($p$-value $\sim 10^{-4}$, accounting for look-elsewhere factors) cross-correlation between CHIME FRBs and galaxies in the redshift range $0.3 \lesssim z \lesssim 0.5$, in three photometric galaxy surveys: WISE$\times$SCOS, DESI-BGS, and DESI-LRG. The level of cross-correlation is consistent with an order-one fraction of the CHIME FRBs being in the same dark matter halos as survey galaxies in this redshift range. We find statistical evidence for a population of FRBs with large host dispersion measure ($\sim 400$ pc cm$^{-3}$), and show that this can plausibly arise from gas in large halos ($M \sim 10^{14} M_\odot$), for FRBs near the halo center ($r \lesssim 100$ kpc). These results will improve in future CHIME/FRB catalogs, with more FRBs and better angular resolution.