Locally Optimally Emitting Clouds and the Origin of Narrow Line Region Emission

Session 4 - Low Luminosity AGN and Starburst Galaxies.
Display session, Monday, June 10
Tripp Commons,

[4.10] Locally Optimally Emitting Clouds and the Origin of Narrow Line Region Emission

J. W. Ferguson, K. T. Korista, G. J. Ferland, D. A. Verner (U. Kentucky)

An essential component to the understanding of active galaxies is narrow line region (NLR) emission. We present new calculations of NLR spectra using the locally optimally emitting cloud (LOC) model. The LOC model assumes that a family of photoionized clouds, in terms of cloud density and distance from the ionizing source, is responsible for narrow line emission. The observed NLR spectrum is a natural consequence of the ability of these `NLR clouds' to reprocess the incident continuum. We compute line diagnostic diagrams and make comparisons with various observations. The AGN temperature conundrum, the [OIII] temperature and [SII] density contradiction, is discussed. We calculate simple Keplerian line profiles of our model NLR and plot the line widths versus critical density.

Program listing for Monday