spectral radiant energy, \(Q_{\lambda}\)

https://doi.org/10.1351/goldbook.ST07480

Derivative of radiant energy, Q, with respect to wavelength λ. SI unit is J m-1; common unit is J nm-1.

Source:
PAC, 2007, 79, 293. 'Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)' on page 425 (https://doi.org/10.1351/pac200779030293)