Comparing X-ray Emission Line Fluxes of NGC 5548 to NGC 1068

TL;DR

This paper compares X-ray emission line fluxes of NGC 5548 and NGC 1068 to test the AGN unification model, revealing discrepancies that suggest additional factors influence observed spectra beyond current models.

Contribution

It provides a comparative analysis of emission fluxes between a Seyfert I and Seyfert II galaxy, highlighting limitations of existing unification models.

Findings

Observed line ratios differ from CLOUDY predictions.

NGC 5548's flux ratios are underpredicted by models.

Additional unknown factors affect AGN emission line ratios.

Abstract

The Unification Model of AGN suggests that all AGN galaxies should exhibit similar line ratios in their spectra. NGC 5548, a Seyfert I, underwent obscuration -- similar to naturally obscured Seyfert II galaxies -- due to an outflowing accretion wind, resulting in absorption. As per the Model, a Seyfert I and a Seyfert II should show similar flux ratios during their respective obscuration states. In this note, we present a comparison of emission fluxes between NGC 5548 and NGC 1068, a Seyfert II. We present the CLOUDY prediction of NGC 5548, which underpredicts the line ratios compared to observations, likely due to SED choices. The differing observed line ratios of NGC 5548 and NGC 1068 suggest additional unknown factors in the unification model.