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What is the origin of the soft excess in AGN?

Malgorzata Sobolewska·Chris Done
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Abstract

We investigate the nature of the soft excess below 1 keV observed in AGN. We use the XMM-Newton data of the low redshift, optically bright quasar, PG 1211+143, and we compare it with the Narrow Line Seyfert 1 galaxy, 1H 0707-495, which has one of the strongest soft excesses seen. We test various ideas for the origin of the soft X-ray excess, including a separate spectral component (for example a low temperature Comptonized component), a reflection-dominated model, or a complex absorption model. All three can give good fits to the data, and $χ^2$ fitting criteria are not sufficient to discriminate among them. Instead, we favor the complex absorption model on the grounds that it is the most physically plausible.

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Malgorzata Sobolewska, Chris Done. 2004-12-20. What is the origin of the soft excess in AGN?. https://doi.org/10.1063/1.1960944

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