The Megamaser Cosmology Project

James Braatz (NRAO), James Condon (NRAO), Mark Reid (Harvard-Smithsonian Center for Astrophysics), Christian Henkel (Max Planck, Bonn), K.Y. Lo (NRAO), Cheng-Yu Kuo (Univ. Virginia), C. M. Violette Impellizzeri (NRAO), and Lei Hao (Univ. Texas)

KSP This is a multi-year project in its third year with a goal of measuring the Hubble Constant Ho to a final accuracy of 3%. To achieve such high precision requires direct geometric distance measurements to circumnuclear water masers in galaxies in the Hubble flow, 50- 200 Mpc distant. All three NRAO instruments (EVLA, GBT and VLBA) are involved in this project.

The NSF National Radio Astronomy Observatory and NSF Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NSF NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NSF NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NSF NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NSF NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.