8 papers · 1 filter
Discovery of Water Maser Emission in Eight AGN with 70-m Antennas of NASA's Deep Space Network
P. T. Kondratko, L. J. Greenhill, J. M. Moran +9
We report the discovery of water maser emission in eight active galactic nuclei (AGN) with the 70-m NASA Deep Space Network (DSN) antennas at Tidbinbilla, Australia and Robledo, Sp…
X-ray Emission from Megamaser Galaxy IC 2560
Greg Madejski, Chris Done, Piotr Zycki +1
Observation of the H2O megamaser galaxy IC 2560 with the Chandra Observatory reveals a complex spectrum composed of soft X-ray emission due to multi-temperature thermal plasma, and…
The Geometry of and Mass Accretion Rate through the Maser Accretion Disk in NGC 4258
J. R. Herrnstein, J. M. Moran, L. J. Greenhill +1
A maximum likelihood analysis of the NGC 4258 maser positions and velocities reveals a ~2 sigma deviation from Keplerian motion in the projected rotation curve of the high-velocity…
A Green Bank Telescope Search for Water Masers in Nearby Active Galactic Nuclei
J. A. Braatz, C. Henkel, L. J. Greenhill +2
Using the Green Bank Telescope, we have conducted a survey for 1.3 cm water maser emission toward the nuclei of nearby active galaxies, the most sensitive large survey for H2O mase…
A Warped Accretion Disk and Wide Angle Outflow in the Inner Parsec of the Circinus Galaxy
L. J. Greenhill, R. S. Booth, S. P. Ellingsen +7
We present the first VLBI maps of H2O maser emission (lambda 1.3cm) in the nucleus of the Circinus Galaxy, constructed from data obtained with the Australia Telescope Long Baseline…
The Discovery of H2O Maser Emission in Seven AGN and at High Velocities in the Circinus Galaxy
L. J. Greenhill, P. T. Kondratko, J. E. J. Lovell +4
We report the discovery of H2O maser emission at 1.35 cm wavelength in seven active galactic nuclei (at distances up to <80 Mpc) during a survey conducted at the 70-m diameter ante…