(Proposal ID) S14B-130

(PI) Yuma, Suraphong

(Proposal Title)
 Follow-up FOCAS Spectroscopy for [O iii] Blobs at z~0.7

(Abstract)
We propose FOCAS spectroscopy for our eight newly selected [O_iii] blobs at 
z~0.7, showing remarkably extended [O_iii] emission larger than 30 kpc down to 
1.2x10^{-18} erg^{-1}cm^{-2} arcsec^{-2} in continuum-subtracted narrowband 
images. This extended oxygen nebulae beyond stellar component is thought to be 
hot metal-right gas outflowing from galaxies. However, without spectroscopy to 
verify gas motion of the system, we cannot certainly conclude that the extended
 feature of [O_iii] emission is caused by gas outflow. With FOCAS, we expect to
 observe Fe_ii, Mg_ii absorption lines and [O_ii}], Hbeta, and [O_iii] emission
 lines, which all fall into optical window at this redshift. We will 1) confirm
 the outflow of these blobs through Fe_ii and/or Mg_ii absorption lines, 2) 
constrain energy source of the outflow (AGN or stellar feedback) through line-
ratio diagnostic diagram, and 3) for the first time investigate if the extended
 oxygen emission is just due to the photo-ionized outflowing gas or involving 
shock heating process through [O_ii]/[O_iii] ratios in extended regions. The 
last goal can only be accomplished with FOCAS optical spectroscopy, which can 
observe both [O_ii] and [O_iii] emission lines simultaneously.