Structure of an Absorbing Medium in the Nucleus of the Galaxy Mrk 417 Based on NuSTAR and Swift/Bat Data
Abstract
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 Γ =1.63-0.11+0.10, absorption NH=3.22-0.39+0.41ṡ1023cm-2). A narrow Fe Kα emission line with an equivalent width EWFeK α=115-1+2e 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 ΓMYTorus=1.68-0.09+0.09 and an absorption along the line of sight of NHI .o .s=3.36-0.07+0.04ṡ1023cm-2 were obtained. The BNTorus model yields a power-law index of ΓBNTorus=1.75-0.09+0.09 and an absorption along the line of sight of NHI .o .s=3.72-0.39+0.49ṡ1023cm-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 Lintr2 - 10keV ∼ 3.16 ṡ 1043erg/s. Additional analysis of the observational data in the near IR indicates that the covering factor may even be smaller, at fc ∼ 0.12. These results indicate that the gas-dust torus is most likely compressed along the vertical and has preferably a ring-like geometry.
- Publication:
-
Astrophysics
- Pub Date:
- September 2020
- DOI:
- 10.1007/s10511-020-09636-1
- Bibcode:
- 2020Ap.....63..307K
- Keywords:
-
- active galactic nuclei;
- gas-dust torus;
- Mrk 417;
- x-radiation