(Proposal ID) S11A-100

(PI) Yagi, Masafumi

(Proposal Title)
Spectroscopy of peculiar extended emission-line regions in the Coma cluster

(Abstract)
We propose to observe 8 extended Halpha regions found in the Coma cluster with 
FOCAS/MOS. The Halpha emitting clouds were detected in our narrow band imaging 
with Suprime-Cam. We have detected total 14 extended Halpha regions, and 6 of 
them have been observed. The aims of this proposal are 1) to measure recession 
velocity of the gas to confirm that they associate with a certain galaxy in the
 nearest Coma cluster galaxy (parent galaxy) and to map their kinematics 
relative to the parent, 2) to measure diagnostic line ratios to set 
constraints on ionizing sources. This observation provide us clues for the 
mechanism of the ionization. The result give us an information on the 
"ongoing" galaxy evolution in nearby clusters.