We present the observations of the reflection nebulae IC 4954 and IC 4955 region with the Infrared Camera and the Far-Infrared Surveyor (FIS) on board the infrared astronomical satellite AKARI during its performance verification phase. We obtained 7 band images from 7 to 160μm with higher spatial resolution and higher sensitivities than previous observations. The spatial variation in the mid-infrared color suggests that the star-formation in IC 4954/4955 is progressing from south-west to north-east. The FIS 4-band data from 65 μm to 160/z m allow us to correctly estimate the total infrared luminosity from the region, which is about one sixth of the energy emitted from the existing stellar sources. Five candidates for young stellar objects have been detected as point sources for the first time in the 11 μm image and it is suggested that that current star-formation has been triggered by previous star-formation activities. A wide area map of the size of about Io around the IC 4954/4955 region was created from the AKARI mid-infrared All-Sky Survey data. Together with the H 121 cm data, it suggests a large hollow structure of a degree scale, on whose edge the IC 4954/4955 region has been created, indicating star formation over three generations in largely different spatial scales.
- ISM: individual (IC 4954, IC 4955)
- Infrared: ISM
- Open clusters: Individual (Roslund 4)
- Stars: star formation
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science