Conclusions

To summarize, 3C445 is a BLRG with unusual X-ray properties which are not easily explained in the current version of the unified models. Its ASCA spectrum is consistent with the presence of a substantial amount of cold matter in the nuclear region, challenging the common notion that the nuclei of type 1 AGN are seen directly.

Clearly, 3C445 is a peculiar BLRG which deserves further spectroscopic follow-up in the X-rays and at other wavelengths. The source qualifies as an excellent target for broad-band SAX observations, which will allow us to refine the measure of the continuum parameters, as well as assessing unambiguously the presence of a Compton hump at high energies and of any scattering component at soft X-rays.

RMS and KN acknowledge financial support from the NRC Research Associate program. IMG and TJT were financially supported through University of Space Research Association. An anonymous referee provided constructive criticism which improved the presentation of the paper. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration, and NASA's Astrophysics Data System Abstract Service.

Figure Captions

• Figure 1: Residuals in the form of ratio of the data to the model for the fit to the ASCA data of 3C445 with a single power law and Galactic column density. The data from the SIS and the GIS detectors are shown separately in the top and bottom panels, respectively. Deviations in the form of a soft excess below 1.5 keV and the Fe line at 6 keV are apparent.
• Figure 2: Results from the fit to the ASCA data with a dual absorber model. (a) Folded model and (b) Residuals, plotted as the ratio of the data to the model. Only the SIS data are shown for clarity, but the fit was performed jointly to both the SIS and GIS detectors. The 5-7 keV region, which was excluded from the fit, has been added back to the plots to show the profile of the Fe K line. The latter is significant at P 99% confidence and has a measured equivalent width of EW 270 eV.
• Figure 3: Contours at 68%, 90%, and 99% confidence for the photon index and covering fraction from a fit with the dual absorber model to the ASCA (dotted line) and ROSAT + ASCA (solid line) data of 3C445. Because of the low signal-to-noise ratio, meaningful contours could be produced only by fixing the column densities to their best-fit values. Note the tighter constraints on the continuum given by the combined ROSAT and ASCA data, illustrating the merits of broad-band observations for 3C445 for measuring the continuum parameters.
• Figure 4: Spectral properties of radio galaxies with published ASCA data. The following quantities are plotted versus the intrinsic (absorption-corrected) 2-10 keV luminosity: (a) Photon index of the continuum, (b) Intrinsic column density N , measured as the difference of the ASCA column density and the Galactic value, and (c) Equivalent Width of the Fe K line. Open circles represent Broad Line Radio Galaxies and filled triangles represent the two Narrow Line Radio Galaxies Centaurus A (at low luminosity) and Cygnus A (at high luminosity). 3C445 is plotted as a filled circle, with constraints from the fits to the joint ROSAT and ASCA data (Figure 3). 3C445 sticks out as a moderately luminous BLRG with the most heavily absorbed X-ray spectrum. Note in panel (a) the narrow distribution of the photon indices around 1.9, similar to Seyfert galaxies.