Modeling IR SED of AGN with Spitzer and Herschel data

TL;DR

This paper investigates the IR spectral energy distribution of AGN using Spitzer and Herschel data, comparing different dust models to understand the dust morphology and the AGN's impact on host galaxy properties.

Contribution

It introduces a new SED fitting procedure utilizing Spitzer and Herschel data to analyze dust distribution and AGN influence on host galaxies.

Findings

Dust properties depend on the chosen dust distribution model.

SED fitting reveals the role of AGN in host galaxy characteristics.

Comparison of modeling approaches highlights the importance of dust morphology.

Abstract

One of the remaining open issues in the context of the analysis of Active Galactic Nuclei (AGN) is the evidence that nuclear gravitational accretion is often accompanied by a concurrent starburst (SB) activity. What is, in this picture, the role played by the obscuring dust around the nucleus and what do the state of the art AGN torus models have to say? Can the IR data provided by Spitzer and Herschel help us in extensively investigate both phenomena and, if so, how and with what limitations? In this paper we present our contribution to the efforts of answering these questions. We show some of the main results coming from a comparative study of various AGN SED modeling approaches, focusing mostly on the much-debated issue about the morphology of the dust distribution in the toroidal structure surrounding the AGN. We found that the properties of dust in AGN as measured by matching observations (be it broad band IR photometry or IR spectra) with models, strongly depend on the choiceof the dust distribution. Then, we present the spectral energy distribution (SED) fitting procedure we developed, making make the best use of Spitzer and Herschel SPIRE mid- and far-IR observations, to dig into the role played by the possible presence of an AGN on the host galaxy's properties.