| Abstract |
Very recent radio, X-ray, and gamma-ray observations have revealed various kinds of high energetic phenomena from interstellar clouds in our Galaxy, such as the shock heating of clouds by supernovae and the production of TeV gamma-rays through interaction of high-energy cosmic-ray particles with clouds. Under such harsh interstellar environments, PAHs are processed and destroyed quite easily, while submicron dust grains survive for a relatively long time, which are collisionally heated to high temperatures. Therefore, spatial variations of the properties of dust and PAHs can provide observational evidence that energetic phenomena really take place in the corresponding regions from entirely different aspects from the radio, X-ray, and gamma-ray observations.
We are currently conducting intensive reduction of AKARI all-sky-survey diffuse data, aiming at the public release of the all-sky maps within a year. By using part of the diffuse maps so far created at 9, 18, 90, and 140 micron, we have made a correlation study of the AKARI all-sky survey with the NANTEN, Suzaku, and HESS data. Among the AKARI data, the 9 micron map is sensitive only to PAHs without contribution from the mid-IR continuum, while the 18 micron map is important to trace shock-heated hot dust. As a result, we find that the ratios of the PAH to dust emission brightness significantly change in the clouds likely associated with high energetic phenomena. In the presentation, we summarize the overall results so far obtained, and also briefly introduce our activities on the all-sky-survey data reduction. |
