Can LISA Resolve Distance to the Large Magellanic Cloud?

Abstract

The Laser Interferometer Space Antenna (LISA) is expected to detect N ~ 22 [x10^(+/- 1)] close white dwarf binaries in the Large Magellanic Cloud (LMC) through their gravitational radiation with signal-to-noise ratios greater than 10 in observational durations of 3 years or more. In addition to chirp mass, location on the sky, and other binary parameters, the distance to each binary is an independent parameter that can be extracted from an analysis of gravitational waves from these binaries. Using a sample of binaries, one can establish the mean distance to the LMC as well as the variance of this distance. Assuming no confusion noise at frequencies above 2 mHz, LISA might determine the LMC distance to ~ 4.5 (N/22)^(1/2)% and the line of sight extent of LMC to ~ 15 (N/22)^(1/4)$%, relative to its distance, at the one-sigma confidence. These estimates are competitive to some of the proposed direct geometric techniques to measure LMC distance in future with missions such as SIM and GAIA.