Potential biases and prospects for the Hubble constant estimation via electromagnetic and gravitational-wave joint analyses

Understand

GW170817 is a binary neutron star merger that exhibited a gravitational wave (GW) and a gamma-ray burst, followed by an afterglow.

• In this work, we estimate the Hubble constant ($H_0$) using broad-band afterglow emission and relativistic jet motion from the Very Long Baseline Interferometry and Hubble Space Telescope images of GW170817.
• Compared to previous attempts, we combine these messengers with GW in a simultaneous Bayesian fit.
• We probe the $H_0$ measurement robustness depending on the data set used, the assumed jet model, the possible presence of a late time flux excess.