The wide-band energy spectrum of NGC 6240 over the range 0.5–200 keV is investigated using the RXTE and ASCA data .
The RXTE data provide the spectrum beyond the ASCA range ( 0.5–10 keV ) with significant detection of signals up to 20 keV and the upper limits above 20 keV .
The spectrum above 10 keV is found to be very flat .
A strong iron-K emission line discovered in the previous ASCA observation is also confirmed with the RXTE PCA .
These results provide further evidence for the dominance of a reflection component , i.e .
emission from cool material illuminated by an AGN .
By fitting the spectra obtained with RXTE and ASCA simultaneously , we satisfactorily modeled the AGN spectrum with a Compton reflection component and probably a transmitted AGN component penetrating through a thick absorber .
The X-ray luminosity of the AGN is estimated to be in the range 4 \times 10 ^ { 43 } -6 \times 10 ^ { 44 } ergs/s in the range 2–10 keV , which categorizes NGC 6240 among the most luminous Seyfert nuclei .
The ratio of the 2–10 keV X-ray luminosity to the infrared luminosity , L _ { X } { ( 2 - 10 ~ { } keV ) } / L _ { IR } , is 0.01 – 0.1 , which implies a quite substantial , if not dominant , contribution of AGN to the infrared luminosity .