2006ApJ...642L..49C

Two-component advective flows have Keplerian accretion disks on the equatorial plane that is surrounded by sub-Keplerian transonic flows. In this Letter, we study the spectral properties of these flows when the shocks are present. The shock acceleration produces nonthermal electrons in the postshock region that in turn produce power-law synchrotron radiation. The soft photons generated by the bremsstrahlung and synchrotron processes in the sub-Keplerian flow, as well as the multicolor blackbody emission from the Keplerian disk, are Comptonized by the thermal and nonthermal electrons. By varying Keplerian and sub-Keplerian rates, we are able to reproduce the observed soft and hard states as far as the X-ray region is concerned and ``low γ-ray intensity'' and ``high γ-ray intensity'' states as far as the soft γ-ray region is concerned. We also find two pivotal points where the spectra intersect, as is observed in, e.g., Cyg X-1.