2009PASP..121..549K

AKARI carries on board the Fourier transform spectrometer (FTS) with the gallium-doped germanium (Ge:Ga) photoconductor arrays of the far-infrared surveyor (FIS). Ge:Ga photoconductors are the most sensitive detectors for far-infrared satellite instruments. However, the performance of these detectors is known to be severely influenced by undesirable slow transient behaviors under a low photon flux condition in space. In fact, we have found that the in-orbit AKARI/FTS data are heavily distorted by the transient response, which severely affects their spectroscopic accuracies. Therefore we have performed transient correction of in-orbit FTS data by using our physical transient model with numerical calculation, by which we have found that the distortion is improved significantly. We have demonstrated the applicability of the physical transient model to FTS data by using the observational data of the Galactic center region.