The absorption spectra of Br-2(center dot-) and Br-3(-) in aqueous solutions are investigated by pulse radiolysis techniques from room temperature to 380 and 350 degrees C, respectively. Br-2(center dot-) can be observed even in supercritical conditions, showing that this species could be used as a probe in pulse radiolysis at high temperature and even under supercritical conditions. The weak temperature effect on the absorption spectra of Br-2(center dot-) and Br-3(-) is because, in these two systems, the transition occurs between two valence states; for example, for Br-2(-) we have (2)Sigma(u) -> (2)Sigma(g) transition. These valence transitions involve no diffuse final state. However, the absorption band of Br- undergoes an important red shift to longer wavelengths. We performed classical dynamics of hydrated Br- system at 20 and 300 degrees C under pressure of 25 MPa. The radial distribution functions (rdfs) show that the strong temperature increase (from 20 to 300 degrees C) does not change the radius of the solvent first shell. On the other hand, it shifts dramatically (by 1 angstrom) the second maximum of the Br-O rdf and introduces much disorder. This shows that the first water shell is strongly bound to the anion whatever the temperature. The first two water shells form a cavity of a roughly spherical shape around the anion. By TDDFT method, we calculated the absorption spectra of hydrated Br- at two temperatures and we compared the results with the experimental data.