# Quasar

• The continuum spectrum of a quasar can often be described, over a broad frequency range, by a power law of the form ${\displaystyle S}$${\displaystyle \nu }$ ${\displaystyle \propto }$ ${\displaystyle \nu }$${\displaystyle \alpha }$ ... where ${\displaystyle \alpha }$ is the spectral index. ${\displaystyle \alpha }$ = 0 corresponds to a flat spectrum, whereas ${\displaystyle \alpha }$ = 1 describes a spectrum in which the same energy is emitted in every logarithmic frequency interval.