An Estimate of H_0 from Keck Spectroscopy of the Gravitational Lens System 0957+561

摘要

These standard errors, however, do not include any contribution from any errors in the assumed form of the mass distribution of the lens. In particular, we used the mass model described by Falco, Gorenstein, & Shapiro, as updated by Grogin & Narayan. The reduced of model fits to the available position and magnification data for this system is relatively high, indicating that the estimate of H_0 may have a significant contribution from model errors. Further observations, discussed herein, should allow such errors to be estimated reliably.