Characterizing the complex absorber in NGC 4151

摘要: We present a detailed analysis of the complex absorption apparent in 2–6 keV X-ray spectrum bright nearby Seyfert galaxy NGC 4151. first utilize large bandpass and medium spectral resolution afforded by BeppoSAX data to construct 1–100 template, which assumes arises both warm (i.e. partially photoionized) cold gas line sight active nucleus source. Application this model an ASCA‘long-look’ observation 4151 reveals partial correlation between underlying continuum flux ionization state absorber. Such is intrinsic property absorber argues strongly favour interpretation for absorbing column over alternative covering models. The has density ∼2 × 1023 cm −2, with parameter range log(ξ) ≈ 2.4–2.7. The inferred relatively low (∼105 cm−3) implies equilibration time-scale dominant ions same order as or longer than variability. It follows that component will invariably be observed non-equilibrium state. may identified multi-temperature wind produced evaporation from inner edge obscuring torus discussed recent paper Krolik & Kriss. unusually character seen then explained terms fortuitous grazes top so intercept substantial gas. We also find (i) reported hardening level falls simply due presence (hard constant) Compton-reflection component, (ii) iron Kα narrow Gaussian profile remains constant short (days) long (months years) time-scales–a relativistically broadened feature was not required our modelling.