The index steepens at X-ray energies due to synchrotron radiation losses and on the average has an X-ray photon index of 1.3–2.3 (spectral index of 2.3–3.3).
该指数在X射线波段由于同步辐射损失而突然增加，而X射线的平均光子指数为1.3–2.3 （光谱指数2.3–3.3）。