The architecture of the active galactic nucleus of NGC 1068

Abstract

NGC 1068 is the brightest and most studied AGN in the sky. Its study motivated the development of the Unified Model for AGN as the prototype of an obscured Seyfert 1 galaxy. The opportunity of studying such object, with IFU spectrographs in the near infrared, allow us to understand the details of how gas is being fed to the central black hole and how the gas is being ionized and ejected from the center. We re-analyzed data taken from the SINFONI (VLT) and NIFS (GEMINI North) public archives, in the HK bands with spatial resolution of 0,1 arcsec (1,7 pc/spaxel). We concentrated our analysis on the molecular H2 lines, the low ionization line [Fe II] and the high ionization line [Si VI]. The analysis shows very distinct behavior for the different lines. In particular we found a clear structure resembling a “glowing-hourglass” shape for the low velocity [Fe II] emission, while the high velocity emission fills the “hourglass”. The shape of this image suggests that the dusty torus and the ionization axis, possibly associated to the central accretion disk, are not co-planar. The primary wind is probably originated from this asymmetry while the secondary wind is likely to be originated from an H2 emitting cloud, about 1” to the north of the AGN, impacted by the primary wind and ionized by the central source.