88 citations · 91 across the 3 of their papers we have counts for
3 papers
Toward a New Distance to the Active Galaxy NGC 4258: II. Centripetal Accelerations and Investigation of Spiral Structure
E. M. L. Humphreys, M. J. Reid, L. J. Greenhill +2
We report measurements of centripetal accelerations of maser spectral components of NGC 4258 for 51 epochs spanning 1994 to 2004. This is the second paper of a series, in which the…
The structure of the accretion disk in NGC 4258 derived from observations of its water vapor masers
Jim Moran, Liz Humphreys, Lincoln Greenhill +2
A wealth of new information about the structure of the maser disk in NGC 4258 has been obtained from a series of 18 VLBA observations spanning three years, as well as from 32 addit…
Recent Progress on a New Geometric Distance to NGC 4258
E. M. L. Humphreys, A. L. Argon, L. J. Greenhill +2
We report on our ongoing, high-resolution study of H2O masers in the innermost parsec of NGC 4258. Over thirty epochs of VLBA and VLA data, taken over six years, are being used to…