The megamaser cosmology project. VI. Observations of ngc 6323

Abstract

We present observations of the H2O megamasers in the accretion disk of NGC 6323. By combining interferometric and spectral monitoring data, we estimate H0=73+26-22km s-1 Mpc-1, where the low strength of the systemic masers (<15 mJy) limits the accuracy of this estimate. The methods developed here for dealing with weak maser emission provide guidance for observations of similar sources, until significant increases in radio telescope sensitivity, such as anticipated from the next generation Very Large Array, are realized.