VLBA21B-117

Resolving the ionized gas disk in the nucleus of NGC 1068

Abstract

The nuclear radio continuum source of NGC 1068 resolves on VLBI baselines. At 5 GHz, it spans about 15 mas (1 pc) and orients at nearly right angles to the radio jet axis. We report the first 22 GHz VLBI continuum image of the nuclear source, obtained as an unanticipated byproduct of HSA observations of the water megamaser disk. On the tapered image, the continuum source has an X-shaped morphology, with one arm of the X lining up with the edge-on water maser disk, and the other appearing to trace a bipolar outflow. The continuum image was produced from off-maser channels, which encompass 16 MHz bandwidth. We propose new HSA observations with 4x 128 MHz bandwidth, to recover the continuum on longer baselines and produce an image with angular resolution matching that of the masers. The primary goal is to look for correspondences between the continuum morphology and the distribution of maser groups to explore the origin of the ionized gas producing the radio continuum. A secondary goal is to improve the absolute astrometry of the maser spots and continuum to study the evolution of the continuum and maser groups, which has never been done before.

Investigators

Name	Institution
Feng Gao	Max-Planck-Institut für Radioastronomie
Jack Gallimore	Bucknell University
Violette Impellizzeri *	National Radio Astronomy Observatory; Leiden, University of; Joint ALMA Observatory
GBT Operator	Green Bank Observatory

* indicates the PI