A Green Bank Telescope Search for Water Masers in Nearby Active Galactic Nuclei.pdf

A GBT Search for Water Masers in Nearby AGNs J. A. Braatz 1 National Radio Astronomy Observatory , 520 Edgemont Rd., Charlottesville, VA 22903 C. Henkel 4 0 0 Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel 69, D-53121 Bonn, Germany 2 c L. J. Greenhill2 and J. M. Moran e D Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 4 1 A. S. Wilson3 1 v Department of Astronomy, University of Maryland, College Park, MD 20742 2 5 3 2 ABSTRACT 1 4 0 Using the Green Bank Telescope, we have conducted a survey for 1.3 cm wa- / h ter maser emission toward the nuclei of nearby active galaxies, the most sensitive p - large survey for H O masers to date. Among 145 galaxies observed, maser emis- 2 o r sion was newly detected in eleven sources and confirmed in one other. Our survey t s −1 ◦ a targeted nearby (v 12,000 km s ), mainly type 2 AGNs north of δ = –20 , : and includes a few additional sources as well. We find that more than a third of v i Seyfert 2 galaxies have strong maser emission, though the detection rate declines X −1 r beyond v ∼ 5000 km s due to sensitivity limits. Two of the masers discovered a during this survey are found in unexpected hosts: NGC 4151 (Seyfert 1.5) and NGC 2782 (starburst). We discuss the possible relat