The Origins Survey Spectrometer (OSS): revealing the hearts of distant galaxies and forming planetary systems with far-IR spectroscopy.

Abstract. The Origins Survey Spectrometer (OSS) is a multi-purpose far-IR spectrograph for Origins. Operating at the photon background limit, OSS covers the 25 to 588 micron wavelength range instantaneously at a resolving power (R) of 300 using six logarithmically-spaced grating modules. Each module couples at least 30 and up to 100 spatial beams simultaneously, enabling true (3D) spectral mapping. In addition, OSS provides two high-resolution modes. The first inserts a long-path Fourier-transform interferometer (FTS) into a portion of the incoming light in advance of the grating backends, enabling R up to 43,000 x [λ/112 μm], while preserving the grating-based sensitivity for line detection. The second incorporates a scanning etalon in series with the FTS to provide R up to 300,000 for the 100–200 μm range.