H-band spectra of CFBDS0059 and ULAS0034

Left panel: H-band spectra of CFBDS0059 and ULAS0034 compared to two of the coolest brown dwarfs previously known (2M0415: T8, Gl570D: T7.5). Right panel : Synthetic spectra for a T= 600K brown dwarf with and without near-infrared NH3 opacity; the NH3 abundance is at its chemical equilibrium value. These models have been developed by Saumon et al. (2000).