SPICA Mid-infrared Instrument (SMI): technical concepts and scientific capabilities

SMI (SPICA Mid-infrared Instrument) is one of the two focal-plane scientific instruments planned for new SPICA, and the Japanese instrument proposed and managed by a university consortium in Japan. SMI covers the wavelength range of 12 to 36 μm, using the following three spectroscopic channels with unprecedentedly high sensitivities: low-resolution spectroscopy (LRS; R = 50 - 120, 17 - 36 μm), mid-resolution spectroscopy (MRS; R = 1300 - 2300, 18 - 36 μm), and high-resolution spectroscopy (HRS; R = 28000, 12 - 18 μm). The key functions of these channels are high-speed dustband mapping with LRS, high-sensitivity multi-purpose spectral mapping with MRS, and high-resolution molecular-gas spectroscopy with HRS. This paper describes the technical concept and scientific capabilities of SMI.