Sub-Parsec-Scale Jet-Driven Water Maser with Possible Gravitational Acceleration in the Radio Galaxy NGC 1052

We report sub-pc-scale observations of the 321-GHz H$_2$O emission line in the radio galaxy NGC 1052. The H$_2$O line emitter size is constrained in $We report sub-pc-scale observations of the 321-GHz H$_2$O emission line in the radio galaxy NGC 1052. The H$_2$O line emitter size is constrained in $