Water-Vapor Maser Disk at the Nucleus of the Seyfert 2 IC 2560 [chapter]

Aya Yamauchi, Yuko Ishihara, Philip Diamond, Naoko Sato, N. Nakai
2008 Astrophysics and Space Science Proceedings  
We observed the H2 O maser at the nucleus of the Seyfert 2, IC 2560, using the VLBA and the phased VLA. The systemic, red-shifted and blue-shifted maser features and a continuum component have been detected. We propose a maser disk in the nuclear region. The systemic and red-shifted features are emitted from a nearly edge-on disk with the position angle of PA = −47 • . The thickness is 2H < 0.025 pc. The binding mass is 3.5 × 10 6 M . Assuming the Keplerian rotation, the radii at the disk are r
more » ... i at the disk are r = 0.087 − 0.335 pc and the rotation velocities are 213-418 km s −1 . The mean density within the inner radius is 1.3 × 10 9 M pc −3 , suggesting a massive black hole at the center. A continuum component is considered as a jet ejected from the nucleus, with an angle of 70 • from the disk. The blue-shifted maser feature is located on the continuum component, being interpreted to be a 'jet maser'.
doi:10.1007/978-0-387-72768-4_121 fatcat:g2t4fnedjvho5ipaqtgrk5qzju