X-ray surveys have revealed a new class of active galactic nuclei ( AGN ) with a very low observed fraction of scattered soft X-rays , f _ { \mathrm { scat } } < 0.5 % .
Based on X-ray modeling these “ X-ray new-type ” , or low observed X-ray scattering ( hereafter : “ low-scattering ” ) sources have been interpreted as deeply-buried AGN with a high covering factor of gas .
In this paper we address the questions whether the host galaxies of low-scattering AGN may contribute to the observed X-ray properties , and whether we can find any direct evidence for high covering factors from the infrared ( IR ) emission .
We find that X-ray low-scattering AGN are preferentially hosted by highly-inclined galaxies or merger systems as compared to other Seyfert galaxies , increasing the likelihood that the line-of-sight toward the AGN intersects with high columns of host-galactic gas and dust .
Moreover , while a detailed analysis of the IR emission of low-scattering AGN ESO 103–G35 remains inconclusive , we do not find any indication of systematically higher dust covering factors in a sample of low-scattering AGN based on their IR emission .
For ESO 103–G35 , we constrained the temperature , mass and location of the IR emitting dust which is consistent with expectations for the dusty torus .
However , a deep silicate absorption feature probably from much cooler dust suggests an additional screen absorber on larger scales within the host galaxy .
Taking these findings together , we propose that the low f _ { \mathrm { scat } } observed in low-scattering AGN is not necessarily the result of circumnuclear dust but could originate from interference of host-galactic gas with a column density of the order of 10 ^ { 22 } \mathrm { cm } ^ { -2 } with the line-of-sight .
We discuss implications of this hypothesis for X-ray models , high-ionization emission lines , and observed star-formation activity in these objects .