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Radiation Temperature or Alpha (trad)

This parameter pulls double duty, used to enter the radiation temperature in units of 10$^7$K in the case of a blackbody or bremsstrahlung input model. It also is used to input the power-law index (in energy), $\alpha$, in the case of a power-law model. Note that $\alpha$ is defined as in $L_\varepsilon\sim\varepsilon^{\alpha}$ so generally $\alpha$ will be less than zero (this is the opposite of the convention used by xspec). XSTAR always works with specific luminosity $L_\varepsilon$ in units erg s$^{-1}$ erg$^{-1}$, and never uses $\varepsilon L_\varepsilon$ or $\nu F_\nu$, for example.

Tim Kallman 2017-04-11