(a–c) A comparison of radiation spectra of a W-PC sample (the red curve) to that of a black-CNT (the blue curve) for T = 575, 630 and 690K, respectively. For all three Ts, the W-PC radiation intensity at λ = 1.7 μm far exceeds the usual blackbody radiation. (d) A summary plot of the exceeding factor η vs. wavelength for T = 575, 630 and 690K, respectively. The black dashed line is for η = 1, which indicates the blackbody limit. At resonances, η is greater than one. η is less than one when off resonances. Inset: a plot of the T-dependence of η at λ = 1.7 μm. The blue line is only a guide for the eyes.