... comes from thermal bremsstrahlung, with a flat power law ( < 1:5 in the Chandra band) or inverse Compton scattering of soft synchrotron photons by the flow electrons, with a steeper X-ray spectral shape (e.g., $ 2:2 has been used to model the nucleus ...
... A single power-law fit is not statistically acceptable, so a broken power-law model is applied as follows: dN dS ( KS bright faint KSbreak S>S S fain t The best-fit slopes for the differential log N log S are bright 2:2 0:2 at the bright end ...
... 3 where S , H , BS ,and BH are typically approximated with the Gehrels prescription (Gehrels 1986 ... 5 The observed background counts are also modeled as independent Poisson random variables, BS $ PoissonreS S ; BH ...