A standard siren cosmological measurement from the potential GW190521 electromagnetic counterpart ZTF19abanrhr

The identification of the electromagnetic (EM) counterpart candidate ZTF19abanrhr to the binary black hole merger GW190521 opens the possibility to infer cosmological parameters from this standard siren with a uniquely identified host galaxy. The distant merger allows for cosmological inference beyond the Hubble constant. Here, we show that the three-dimensional spatial location of ZTF19abanrhr calculated from the EM data remains consistent with the latest sky localization of GW190521 provided by the LIGO-Virgo Collaboration. If ZTF19abanrhr is associated with the GW190521 merger, and assuming a flat omega CDM model, we find that H-0 = 48(-10)(+23) km s(-1) Mpc(-1), Omega(m)= 0.35(-0.26)(+0.41), and omega(0) = -1.31(-0.48)(+0.61) (median and 68 per cent credible interval). If we use the Hubble constant value inferred from another gravitational-wave event, GW170817, as a prior for our analysis, together with assumption of a flat ACDM and the model-independent constraint on the physical matter density omega(m) from Planck, we find H-0 = 68.9(-6.0)(+8.7) km s(-1) Mpc(-1).

Automated summary

This study explores the possibility of inferring cosmological parameters using the standard siren ZTF19abanrhr, which is associated with the binary black hole merger GW190521. The results provide estimates of the Hubble constant and matter density under different models and priors.