Research On AGN NLR And Torus

Narrow Line Region(NLR) is one of the few structures in Active Galactic Nu-clei (AGN) that could be resolved. It tells us the gas distribution and kinematic information from the nuclei all the way to the host galaxy bulge, thus is a pow-erful tool to understand the structure of the nuclei and the interaction between AGN and the host galaxy. In this dissertation, we perform a systematic study of the narrow line strength, Equivalent Width(EW), and kinematic. In Chap-ter.2, we explore what is the governing factor of [O Ⅲ] EW. Using a0<z<0.8Seyfertl galaxy sample with reliable emission line and continuum measurements culled from Sloan Digital Sky Survey fourth Data Release(SDSS DR4), we find that EW([O Ⅲ]) correlate weakly with fundamental AGN activity parameters like luminosity, black hole mass and L/LEdd.By further decomposing [O Ⅲ] into sta-tic narrow core component and blueshifted broad wing component, we find the EW(core) correlate well with the luminosity weighted velocity of [O Ⅲ]. Possi-ble reasons of this correlation include inclination effect and different interstellar medium in host galaxy. In Chapter.3, we find that the slope of relationship be-tween EW of narrow lines (including [O Ⅲ]) and luminosity (Baldwin effect, BEff for short) all cluster near-0.2. The lines show large deviation are attributable to starformation contamination, metallicity effect or change of continuum shape. We propose a simple continuum variability model to explain this result. The contin-uum variability here include intrinsic variability and continuum inclination effect. In Chapter.4, we select a broad line AGN sample with redshift less than0.3and find that:given the same AGN luminosity, the [O Ⅲ] luminosity is systematic lower in sources with higher broad line extinction. This means the obscuring ma-terial of broad line region also obscure part of NLR. This result provides constraint on the outer radius of AGN torus. In Chapter.5, we study the relation between torus and NLR outflow. By cross-correlating WISE Preliminary Data Release and the sample that has accurate emission line and continuum measurement stated in Chapter.2, we obtain3.4to22micron infrared photometry for about one third of the sources. Correlation analysis indicate the L22vm/Lbol strongly correlate with EW(wing) but show much weaker correlation with core component. A natural explanation is:the torus not only confines the ionization core, but also provides source of gas for [O Ⅲ] outflow.