Infrared absorption spectra of hot ammonia

Infrared absorption spectra of NH3 have been obtained at high resolution (0.02 cm−1) at seven temperatures between 296 and 973 K. The spectra were recorded using a Bruker IFS 125 infrared Fourier transform spectrometer in the 2400-5500 cm−1 region and empirical lower state energies have been obtained by comparison of line strengths at different temperatures. Using two reference line lists, quantum number assignments have been made for each temperature for between 1660 and 3020 transitions, with J up to 22. The line lists obtained provide accurate line positions as well as intensities and experimental lower state energies at temperatures relevant for modeling the atmospheres of brown dwarfs and exoplanets.