Structure of an Absorbing Medium in the Nucleus of the Galaxy Mrk 417 Based on NuSTAR and Swift/Bat Data

We present the results of X-ray spectral analysis of the Seyfert type 2 galaxy Mrk 417 ( ɀ ≈ 0.0327 ) based on data from the NuSTAR (3-60 keV) and Swift/BAT (14-150 keV) space observatories. The spectrum from the NuSTAR observatory is well described by a basic power-law model with neutral absorption and an additional reflection component from a cold neutral medium (power-law index $\Gamma ={1.63}_{-0.11}^{+0.10}$, absorption ${\mathrm{N}}_{\mathrm{H}}={3.22}_{-0.39}^{+0.41}\cdot {10}^{23}{cm}^{-2}$). A narrow Fe K_α emission line with an equivalent width ${\mathrm{EW}}_{{\mathrm{FeK}}_{\upalpha}}={115}_{-1}^{+2}e\mathrm{V}$ is present and indicates a moderate density of the medium in which this line is formed. The NuSTAR data together with the Swift/BAT data were analyzed using the more complicated physical models MYTorus and BNTorus. In the first case a power-law index ${\Gamma}_{\mathrm{MYTorus}}={1.68}_{-0.09}^{+0.09}$ and an absorption along the line of sight of ${\mathrm{N}}_{\mathrm{HI}.\mathrm{o}.\mathrm{s}}={3.36}_{-0.07}^{+0.04}\cdot {10}^{23}{cm}^{-2}$ were obtained. The BNTorus model yields a power-law index of ${\Gamma}_{\mathrm{BNTorus}}={1.75}_{-0.09}^{+0.09}$ and an absorption along the line of sight of ${\mathrm{N}}_{\mathrm{HI}.\mathrm{o}.\mathrm{s}}={3.72}_{-0.39}^{+0.49}\cdot {10}^{23}{cm}^{-2}$. These results provide an estimate of the covering factor for the gas-dust torus of fc ≈ 0.29 − 0.34 and derive absorption-corrected X-ray luminosity of L_{intr2 ‐ 10keV} ∼ 3.16 ⋅ 10⁴³erg/s. Additional analysis of the observational data in the near IR indicates that the covering factor may even be smaller, at f_c ∼ 0.12. These results indicate that the gas-dust torus is most likely compressed along the vertical and has preferably a ring-like geometry.