A.A. Passchier, J.D. Christian, and N.W. Gregory, "The ultraviolet-visible absorption spectrum of bromine between room temperature and 440 °C," J. Phys. Chem. 71, 937-942 (1967), and

W.Y. Wen and R.M. Noyes, "Ultraviolet spectra of single and double molecules of gaseous bromine," J. Phys. Chem. 76, 1017-1018 (1972),

to a four-band semi-logarithmic Gaussian distribution function (eqn. 22):

σ(298 K) =
1.06×10^-20 cm² × exp{-52.3[ln(223.3 nm/λ)]²} +
6.19×10^-19 cm² × exp{-108.5[ln(411.9 nm/λ)]²} +
3.39×10^-19 cm² × exp{-106.8[ln(480.2 nm/λ)]²} +
3.78×10^-20 cm² × exp{-112.0[ln(549.3 nm/λ)]²}