AKARI observations of the ISM in our Galaxy and nearby galaxies Original Research Article

With AKARI, we have systematically performed near- to far-infrared (NIR–FIR) observations of the interstellar medium (ISM) in our Galaxy and nearby galaxies as one of AKARI mission programs called ISMGN (ISM in our Galaxy and Nearby galaxies). Our scientific objective is to increase our knowledge on the properties of the ISM exposed to an extensive range of environments, the processing, evolution, and destruction of interstellar dust, and their connection with physical conditions of interstellar gas and star-forming activity. Our Galaxy contains ideal laboratories for probing the life cycle of the ISM, while nearby external galaxies provide a much wider range of physical conditions. We present the contents of the AKARI observations relevant to our ISM studies, together with some results demonstrative of the AKARI uniqueness obtained during the AKARI cold mission phase (Phases 1 and 2). For the ISM in our Galaxy and the LMC, we have performed spectroscopic observations of several regions intensively in the NIR to FIR, including detailed studies of 14 Galactic and 21 LMC SNRs. We have observed about 60 nearby galaxies, for many of which NIR to FIR images in the 10 photometric bands centered at the wavelengths of 3, 4, 7, 11, 24, 15, 65, 90, 140, and image as well as 2–14 image low-resolution spectra are obtained. Our data, especially the 11 and image imaging, the FIR 4-band imaging, and the NIR spectral data will be complementary to the Spitzer data of nearby galaxies such as those from the SINGS legacy program. We further refer to our on-going observations in the AKARI post-helium mission phase (Phase 3).