A multicloud model is presented which explains the soft X-ray excess in NGC 4051 and, consistently, the optical line spectrum and the spectral energy distribution (SED) of the continuum. The clouds are heated and ionized by the photoionizing flux from the active center and by shocks. Diffuse radiation, partly absorbed throughout the clouds, nicely fits the bump in the soft X-ray domain, while bremsstrahlung radiation from the gaseous clouds contributes to the fit of the continuum SED. Debris from high-density fragmented clouds are necessary to explain the absorption oxygen throats observed at 0.87 and 0.74 keV. The debris are heated by shocks of about 200-300 km s-1. Low-velocity (≤100 km s-1), low-density (100 cm-3) clouds contribute to the line and continuum spectra, as well as high-velocity (1000 km s-1), high-density (8000 cm-3) clouds that are revealed by the FWHM of the line profiles. The SED in the IR is explained by reradiation of dust; however, the dust-to-gas ratio is not particularly high (≤ 3 × 10-15). Radio emission is well fitted by synchrotron radiation created at the shock front by a Fermi mechanism.
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机译：提出了一个多云模型，该模型解释了NGC 4051中的软X射线过量，并一致地解释了连续谱的光线光谱和光谱能量分布（SED）。云被来自活动中心的光电离通量和电击加热并电离。漫辐射（部分被整个云吸收）很好地适合了软X射线域中的凹凸，而气态云的致辐射有利于连续SED的拟合。来自高密度碎片云的碎片对于解释在0.87和0.74 keV处观察到的吸收氧喉是必要的。碎片通过约200-300 km s-1的冲击加热。低速（≤100km s-1），低密度（100 cm-3）的云有助于线谱和连续谱，以及高速（1000 km s-1），高密度（8000 cm） -3）由线轮廓的FWHM显示的云。红外辐射中的SED可以通过重新辐射灰尘来解释。但是，粉尘/气体比不是特别高（≤3×10-15）。费米机构在激波前沿产生的同步加速器辐射非常适合无线电发射。
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