ASTRO-F, super-IRAS, the All-Sky Infrared Survey

We review the next-generation Japanese infrared space mission, ASTRO-F. ASTRO-F will be the first survey of the entire sky at infrared wavelengths since the IRAS mission almost 20 years ago. ASTRO-F will survey the entire sky in four far-infrared bands from 50 to 200 μm and two mid-infrared bands at 9 and 20 μm to sensitivities 10-1000 times deeper than the IRAS satellite at angular resolutions of 25-45 arcsec (cf. 2-5 arcmin for IRAS). ASTRO-F can be considered as a super-IRAS. Using the galaxy evolution model of Pearson, we produce expected numbers of sources under three different cosmological world models. We predict that ASTRO-F will detect of the order of tens of millions of sources in the far-infrared wavelength bands, most of which will be dusty luminous infrared/ultraluminous infrared galaxies, of which as many as half will lie at redshifts greater than unity. We produce number-redshift distributions, flux-redshift and colour-colour diagrams for the survey and discuss various segregation and photometric redshift techniques. Furthermore, we investigate the large-scale structure scales that will be accessed by ASTRO-F, discovering that ASTRO-F and SIRTF-SWIRE probe both different scales and redshift domains and concluding that the two missions will supplement rather than supplant one another.