Intermediate-mass-ratio-inspirals in the Einstein Telescope. II. Parameter estimation errors.

We explore the precision with which the Einstein Telescope will be able to measure the parameters of intermediate-mass-ratio inspirals, i.e., the inspirals of stellar mass compact objects into intermediate-mass black holes (IMBHs). We calculate the parameter estimation errors using the Fisher Matrix formalism and present results of Monte Carlo simulations of these errors over choices for the extrinsic parameters of the source. These results are obtained using two different models for the gravitational waveform which were introduced in paper I of this series. These two waveform models include the inspiral, merger, and ringdown phases in a consistent way. One of the models, based on the transition scheme of Ori and Thorne [A. Ori and K. S. Thorne, Phys. Rev. D 62, 124022 (2000)], is valid for IMBHs of arbitrary spin; whereas, the second model, based on the effective-one-body approach, has been developed to cross-check our results in the nonspinning limit. In paper I of this series, we demonstrated the excellent agreement in both phase and amplitude between these two models for nonspinning black holes, and that their predictions for signal-to-noise ratios are consistent to within 10%. We now use these waveform models to estimate parameter estimation errors for binary systemsmore » with masses 1.4M{sub {circle_dot}}+100M{sub {circle_dot}}, 10M{sub {circle_dot}}+100M{sub {circle_dot}}, 1.4M{sub {circle_dot}}+500M{sub {circle_dot}}, and 10M{sub {circle_dot}}+500M{sub {circle_dot}} and various choices for the spin of the central IMBH. Assuming a detector network of three Einstein Telescopes, the analysis shows that for a 10M{sub {circle_dot}} compact object inspiralling into a 100M{sub {circle_dot}} IMBH with spin q=0.3, detected with a signal-to-noise ratio of 30, we should be able to determine the compact object and IMBH masses, and the IMBH spin magnitude to fractional accuracies of {approx}10{sup -3}, {approx}10{sup -3.5}, and {approx}10{sup -3}, respectively. We also expect to determine the location of the source in the sky and the luminosity distance to within {approx}0.003 steradians and {approx}10%, respectively. We also compute results for several different possible configurations of the detector network to assess how the precision of parameter determination depends on the network configuration.« less