Positional coincidence between an H2O maser and a plasma torus in NGC 1052

We present VLBA observation towards the nucleus of a nearby radio galaxy NGC 1052. In NGC 1052, two-sided jet structure and a dense plasma circumnuclear torus with a radius of 0.7 pc have been found around the central mass. It emits a H₂O megamaser, which is redshifted with respect to the systemic velocity of the galaxy (1491 kms⁻¹) with a large velocity width of 100 kms⁻¹ (FWHM). The maser gas is found at the inner jet components of both the approaching and receding jets. The maser gas is positionally coincident with a plasma torus. The maser gas in NGC 1052 could be explained as a circumnuclear torus or disk, as found for the nucleus of NGC 4258.