GV016

Co-existence of gas states and velocities in the ineer parsec of NGC 1052

Abstract

NGC 1052 is bright, nearby, and provides an excellent opportunity to study the sub-pc environment of an AGN: the ionized (free-free absorbing), atomic (HI absorbing), and molecular (OH absorbing and H20 emitting) gas components. Spatially unresolved WSRT spectra show that OH absorption spans the full velocity range seen in HI. The OH1667/1665 line ratio varies with velocity; we plan non-LTE modeling based on the proposed images. We argue that the OH molecular gas could well be co-located with the atomic HI, which we find towards the forward-pointing jet. But H2O masing molecular gas occurs along the receeding jet, albeit in a limited velocity range. At that velocity we have not found HI any closer to the nucleus than ~1-1.5 pc along the forward jet. There could be a central hole in the atomic/molecular gas; we now need high sensitivity to measure or constrain the HI opacity on the receeding side of the necleus. There are OH/HI line profile differences, but our current observations are not contemporaneous. To unravel the kinematic and excitation structure requires high sensitivity co-eval VLBI images in OH and HI.

Front Ends

Gregorian L(1.15 to 1.73 GHz)

Back Ends

VLBA recorder and DAR

Type of Observing

Very Long Baseline Interferometry

Switching Type

Created: Sun Sep 15 10:04:41 Eastern Daylight Time 2002