The Far-Infrared Surveyor (FIS) for AKARI

Abstract

The Far-Infrared Surveyor (FIS) is one of two focal plane instruments on the AKARI satellite. FIS has four photometric bands at 65, 90, 140, and 160 µm, and uses two kinds of array detectors. The FIS arrays and optics are designed to sweep the sky with high spatial resolution and redundancy. The actual scan width is more than eight arcmin, and the pixel pitch is matches the diffraction limit of the telescope. Derived point spread functions (PSFs) from observations of asteroids are similar to the optical model. Significant excesses, however, are clearly seen around tails of the PSFs, whose contributions are about 30% of the total power. All FIS functions are operating well in orbit, and its performance meets the laboratory characterizations, except for the two longer wavelength bands, which are not performing as well as characterized. Furthermore, the FIS has a spectroscopic capability using a Fourier transform spectrometer (FTS). Because the FTS takes advantage of the optics and detectors of the photometer, it can simultaneously make a spectral map. This paper summarizes the in-flight technical and operational performance of the FIS.

Clustering of far-infrared galaxies in the AKARI All-Sky Survey North

“…The effective size of the point spread function of AKARI FIS in FWHM is estimated to be 37 ± 1 , 39 ± 1 , 58 ± 3 , and 61 ± 4 at 65 μm, 90 μm, 140 μm, and 160 μm, respectively (Kawada et al, 2007). An additional noise factor to be considered is the source confusion: however, in the case of the AKARI data the source confusion limit is estimated to be generally fainter than the detection limit (Jeong et al, 2005(Jeong et al, , 2006.…”

“…1 AKARI was equipped with a cryogenically cooled telescope of 68.5-cm aperture diameter and two scientific instruments, the Far-Infrared Surveyor (FIS; Kawada et al, 2007) and the Infrared Camera (IRC; Onaka et al, 2007).…”

Clustering of far-infrared galaxies in the AKARI All-Sky Survey

“…The effective size of the point spread function of AKARI FIS in FWHM is estimated to be 37 ± 1 , 39 ± 1, 58 ± 3 , and 61±4 at 65 μm, 90 μm, 140 μm, and 160 μm, respectively (Kawada et al, 2007). Errors are not estimated for each individual source, but instead they are, in total, estimated to be 35%, 30%, 60%, and 60% at 65 μm, 90 μm, 140 μm, and 160 μm, respectively (Yamamura et al, 2010).…”

“…1 AKARI is equipped with a cryogenically cooled telescope of 68.5 cm aperture diameter and two scientific instruments, the Far-Infrared Surveyor (FIS; Kawada et al, 2007) and the Infrared Camera (IRC; Onaka et al, 2007).…”

AKARI All Sky Survey: contribution from AGB stars to the far infrared flux from the Milky Way related to point sources outside the Galactic plane

“…1 AKARI is equipped with a cryogenically-cooled telescope of 68.5 cm aperture diameter and two scientific instruments, the Far-Infrared Surveyor (FIS; Kawada et al, 2007) and the Infrared Camera (IRC; Onaka et al, 2007). Among various astronomical observations performed by AKARI, an all sky survey with FIS and IRC has been carried out; it is referred to as the AKARI All-Sky Survey.…”