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We present an empirical model of Comptonization for fitting the spectra of X-ray binaries. This model, simpl, has been developed as a package implemented in XSPEC. With only two free parameters, simpl is competitive as the simplest empirical model of Compton scattering. Unlike other empirical models, such as the standard power-law model, simpl incorporates the basic physics of Compton scattering of soft photons by energetic coronal electrons. Using a simulated spectrum, we demonstrate that simpl closely matches the behavior of physical Comptonization models which consider the effects of optical depth, coronal electron temperature, and geometry. We present fits to RXTE spectra of the black-hole transient H1743-322 and a BeppoSAX spectrum of LMC X-3 using both simpl and the standard power-law model. A comparison of the results shows that simpl gives equally good fits and a comparable spectral index, while eliminating the troublesome divergence of the standard power-law model at low energies. Importantly, simpl is completely flexible and can be used self-consistently with any seed spectrum of photons. We show that simpl - unlike the standard power law - teamed up with diskbb (the standard model of disk accretion) gives results for the inner-disk radius that are unaffected by strong Comptonization, a result of great importance for the determination of black hole spin via the continuum-fitting method.
This work presents a novel derivation of the expressions that describe the distortions of the cosmic microwave background curve due to the interactions between photons and the electrons present in dilute ionized systems. In this approach, a simplifie
A simple model of quintessential inflation with the modified exponential potential $e^{-alpha phi} [A+(phi-phi_0)^2]$ is analyzed in the braneworld context. Considering reheating via instant preheating, we conclude that the model exhibits transient a
In this Letter we propose a simple thermal comptonization model to account for the observed properties of the phase lags associated to the ``plateau intervals of GRS 1915+105. By invoking a temperature stratification in a corona and assuming that the
After a rapid introduction about the models of comptonization, we present some simulations that underlines the expected capabilities of Simbol-X to constrain the presence of this process in objects like AGNs or XRB.
We propose a simple model with the Z_N symmetry in order to answer whether the symmetry is a good concept in QCD with light quark mass. The model is constructed by imposing the flavor-dependent twisted boundary condition (TBC) on the three-flavor Pol