Redshift Dependence of Stochastic Gravitational Wave Background and Galaxy Overdensity Cross-Correlation

Abstract

Following [1], the cross-correlation between the stochastic gravitational wave background (SGWB) due to binary black hole mergers and the sky distribution of galaxies was computed. The SGWB anisotropies are obtained from the third observing run (O3) of Advanced LIGO, and the galaxy distribution was taken from the Sloan Digital Sky Survey (SDSS) spectroscopic catalogue. The angular power of the cross-correlation in 10Hz wide GW frequency bins and 0.1 wide redshift bins was found to be noise-dominated. The resulting angular cross-rcross-correlation power spectra were used to find the maximum likelihood estimates for parameters to a simplified astrophysical kernel with amplitude Amax and redshift center zc. No constraints were able to be placed on the redshift, but a 95% confidence upper-limit was found for Amax = 8.3 × 10−33erg/cm3s1/3. This analysis was limited by the redshift range of the catalogue and GW sensitivity. As data sensitivity grows, better estimates for the bound of the astrophysical kernel will be found.