(Proposal ID) S13B-151

(PI) Shimonishi, Takashi

(Proposal Title)
Spatial Distribution of Ices and Gas in Cepheus A East

(Abstract)
We propose M-band spectroscopic observations with Subaru/IRCS Echell 
spectrometer toward a massive star-forming region, Cepheus A East. One of the 
key issues to understand the formation and evolution history of ices in star-
forming regions is to shed the light on the processing of ices by nearby 
protostars. However, previous observations of ices mainly aimed to obtain 
single line-of-sight information due to observational constraints. Thus our 
knowledge about spatial distribution of ices in a protostellar environment is 
limited. Our infrared spectroscopic observations with AKARI suggest spatial 
variations of ice absorption features around a protostellar object in Cepheus 
A East. The result suggests the thermal processing of ices by a protostar. The 
proposed observations aims to understand the thermal evolution of ices in the 
region by investigating the CO ice and CO gas absorption bands. Futhermore, we 
try to identify the newly detected unknown emission-like feature in Cepheus 
A East. By combining the present observations and previously obtained AKARI 
and Spitzer spectral data, we can obtain a complete data set of major ice 
species, dust, gas, and their spatial distribution in a star-forming region.