Abstract
As the theme for the future L3 Cosmic Vision mission, ESA has recently chosen the “Gravitational Wave Universe.” Within this program, a mission concept called eLISA has been proposed. This observatory has a current initial configuration consisting of four laser links between the three satellites, which are separated by a distance of one million kilometers, constructing a single-channel Michelson interferometer. However, the final configuration for the observatory will not be fixed until the end of this decade. With this in mind, we investigate the effect of different eLISA-like configurations on massive black hole detections. This work compares the results of a Bayesian inference study of 120 massive black hole binaries out to a redshift of for a arm length eLISA with four and six links, as well as a arm length observatory with four links. We demonstrate that the original eLISA configuration should allow us to recover the luminosity distance of the source with an error of less than 10% out to a redshift of , and a sky error box of out to . In contrast, both alternative configurations suggest that we should be able to conduct the same parameter recovery with errors of less than 10% in luminosity distance out to and out to . Using the information from these studies, we also infer that if we were able to construct a 2 Gm, six-link detector, the above values would shift to for luminosity distance and for sky error. While the final configuration will also be dependent on both technological and financial considerations, our study suggests that increasing the size of a two-arm detector is a viable alternative to the inclusion of a third arm in a smaller detector. More importantly, this work further suggests no clear scientific loss between either choice.
- Received 29 June 2015
DOI:https://doi.org/10.1103/PhysRevD.92.064001
© 2015 American Physical Society