paper

Fe-K line probing of material around the AGN central engine with Suzaku

arXiv:1011.1750 · doi:10.1088/0004-637X/727/1/19

Abstract

We systematically analyzed the high-quality Suzaku data of 88 Seyfert galaxies. We obtained a clear relation between the absorption column density and the equivalent width of the 6.4 keV line above 10 cm, suggesting a wide-ranging column density of cm with a similar solid and a Fe abundance of 0.7--1.3 solar for Seyfert 2 galaxies. The EW of the 6.4 keV line for Seyfert 1 galaxies are typically 40--120 eV, suggesting the existence of Compton-thick matter like the torus with a column density of cm and a solid angle of , and no difference of neutral matter is visible between Seyfert 1 and 2 galaxies. An absorber with a lower column density of cm for Compton-thin Seyfert 2 galaxies is suggested to be not a torus but an interstellar medium. These constraints can be understood by the fact that the 6.4 keV line intensity ratio against the 10--50 keV flux is almost identical within a range of 2--3 in many Seyfert galaxies. Interestingly, objects exist with a low EW, 10--30 eV, of the 6.4 keV line, suggesting that those torus subtends only a small solid angle of . Ionized Fe-K emission or absorption lines are detected from several percents of AGNs. Considering the ionization state and equivalent width, emitters and absorbers of ionized Fe-K lines can be explained by the same origin, and highly ionized matter is located at the broad line region. The rapid increase in EW of the ionized Fe-K emission lines at cm is found, like that of the cold material. It is found that these features seem to change for brighter objects with more than several erg/s such that the Fe-K line features become weak. We discuss this feature, together with the torus structure.

arXiv comment32 pages, 20 figures, ApJ accepted

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