AKARI Far-Infrared All Sky Survey

TL;DR

The AKARI satellite conducted a comprehensive all-sky far-infrared survey from 50 to 180 micrometers, significantly surpassing IRAS in resolution and sensitivity, providing valuable data for studying diffuse emission.

Contribution

This paper presents the first high-resolution, sensitive all-sky far-infrared map from AKARI, improving upon previous surveys and addressing detector stability and data quality issues.

Findings

Achieved all-sky coverage of over 94% during 2006-2007.

Provided the first high-resolution data beyond 100 micrometers.

Demonstrated the reliability and potential for high-quality diffuse emission maps.

Abstract

We demonstrate the capability of AKARI for mapping diffuse far-infrared emission and achieved reliability of all-sky diffuse map. We have conducted an all-sky survey for more than 94 % of the whole sky during cold phase of AKARI observation in 2006 Feb. -- 2007 Aug. The survey in far-infrared waveband covers 50 um -- 180 um with four bands centered at 65 um, 90 um, 140 um, and 160 um and spatial resolution of 3000 -- 4000 (FWHM).This survey has allowed us to make a revolutionary improvement compared to the IRAS survey that was conducted in 1983 in both spatial resolution and sensitivity after more than a quarter of a century. Additionally, it will provide us the first all-sky survey data with high-spatial resolution beyond 100 um. Considering its extreme importance of the AKARI far-infrared diffuse emission map, we are now investigating carefully the quality of the data for possible release of the archival data. Critical subjects in making image of diffuse emission from detected signal are the transient response and long-term stability of the far-infrared detectors. Quantitative evaluation of these characteristics is the key to achieve sensitivity comparable to or better than that for point sources (< 20 -- 95 [MJy/sr]). We describe current activities and progress that are focused on making high quality all-sky survey images of the diffuse far-infrared emission.