Following the first Public Release of the AKARI Point Source catalogues, we have worked on the production of a new far-infrared All-Sky Diffuse mapping product. In this paper we report first results from the All Sky diffuse maps that will shortly be released to the community, based on analysis of data from the Far Infrared Surveyor ( 65 μm − 160 μm ) instrument. These data are likely to have a strong impact on studies of extended structures, and the diffuse ISM.

We observed an area of 10 d e g 2 of the Large Magellanic Cloud using the Infrared Camera (IRC) onboard AKARI. The observations were carried out using five imaging filters (3, 7, 11, 15, and 24 μm ) and the prism disperser ( 2 − 5 μm , λ/Δλ ∼ 20 ) equipped in the IRC. This paper presents an outline of the survey project and also describes very briefly the newly compiled near- to mid-infrared point source catalog. The 10σ limiting magnitudes are 17.9, 13.8, 12.4, 9.9, and 8.6 mag at 3.2, 7, 11, 15 and 24 μm , respectively. The photometric accuracy is estimated to be about 0.1 mag at 3.2 μm and 0.06 - 0.07 mag in the other bands. The position accuracy is 0.3" at 3.2, 7 and 11 μm and 1.0" at 15 and 24 μm . The sensitivities at 3.2, 7, and 24 μm are roughly comparable to those of the Spitzer SAGE LMC point source catalog, while the AKARI catalog provides the data at 11 and 15 μm , covering the near- to mid-infrared spectral range continuously.

Far-infrared observations provide crucial data for the investigation and characterisation of the properties of dusty material in the Interstellar Medium (ISM), since most of its energy is emitted between ~ 100 and 200 μm . We present the first all-sky image from a sensitive all-sky survey using the Japanese AKARI satellite, in the wavelength range 50 − 180 μm . Covering > 99% of the sky in four photometric bands with four filters centred at 65 μm , 90 μm , 140 μm , and 160 μ m wavelengths, this achieved spatial resolutions from 1 to 2 arcmin and a detection limit of < 10 MJy s r − 1 , with absolute and relative photometric accuracies of < 20%. All-sky images of the Galactic dust continuum emission enable astronomers to map the large-scale distribution of the diffuse ISM cirrus, to study its thermal dust temperature, emissivity and column density, and to measure the interaction of the Galactic radiation field and embedded objects with the surrounding ISM. In addition to the point source population of stars, protostars, star-forming regions, and galaxies, the high Galactic latitude sky is shown to be covered with a diffuse filamentary-web of dusty emission that traces the potential sites of high latitude star formation. We show that the temperature of dust particles in thermal equilibrium with the ambient interstellar radiation field can be estimated by using 90 μm , 140 μm , and 160 μm data. The FIR AKARI full-sky maps provide a rich new data set within which astronomers can investigate the distribution of interstellar matter throughout our Galaxy, and beyond.