Oral Presentation

Warm Debris Disks Proved by AKARI Observations

Hideaki Fujiwara (Subaru Telescope, National Astronomical Observatory of Japan)

Debris disks around main-sequence stars are expected to be related to the stability of minor bodies and, potentially, to the presence of planets around stars. Recent high-sensitivity observations in the mid-infrared allow us to investigate the properties of warm dust grains in the inner region of debris disks, which should have a more direct link to the formation of terrestrial planets than the low-temperature dust that has been previously studied. Here we report the results of our survey of warm debris disks based on photometric measurements at 18 micron taken from the AKARI/IRC All-Sky Survey data. We have identified 24 debris disk candidates with bright mid-infrared excess emission above the stellar photospheric emission out of the 856 sources that were detected at 18 micron. We find that A stars and solar-type FGK stars have different characteristics of their debris disks. We also show the results of our follow-up observations of the AKARI-identified warm debris disks in the mid- and far-infrared and discuss their nature.