Multimessenger Parameter Estimation of GW170817: From Jet Structure to the Hubble Constant

The electromagnetic radiation that followed the neutron star merger event GW170817 revealed gamma-ray burst afterglows from jets misaligned with our line of sight exhibit a light curve slowly rising flux. slope depends sensitively on angle observer respect to jet axis, which is likely be perpendicular plane binary. Therefore, afterglow emission can used constrain inclination merging system. Here, we calculate based realistic structure derived general-relativistic magnetohydrodynamical simulations black hole torus system for central engine burst. Combined gravitational wave parameter estimation, fit multi-epoch GW170817. We show such model, observing tightly constrained by multi messenger observations. best $\theta_{\rm v} = 0.38\pm 0.02$ rad. With constraint, break degeneracy between and luminosity distance in substantially increase precision Hubble constant standard siren method. Our estimation $D_{\rm L}=43.4\pm 1\ \rm Mpc$ constraint $69.5\pm 4\ \mathrm{km\ s^{-1}\ Mpc^{-1}}$. As result, multimessenger observations short-duration bursts, combined good theoretical understanding structure, powerful probes cosmological parameters.