Dense Ionized Outflow with Five Narrow Components in a Dust-obscured Galaxy

We present our discovery of a complex ionized outflow in SDSS J101034.28+372514.7 (J1010+3725), a dust-obscured galaxy (DOG) at $z=0.282$. The SDSS optical spectrum of J1010+3725 shows five narrow components with one broad component in [O{,\sc iii}]$\lambda$5007, which represents one of the most complex outflow structures observed among dusty active galactic nuclei. Spectrum fitting shows that the five narrow components have a wide range of velocity shifts (from $-1475$ to $+507$ km s${}^{-1}$). The possible multiple peaks are also observed in [O{,\sc iii}]$\lambda$4363 and [Ne{,\sc iii}]$\lambda$3868, which allows us to investigate the physical condition of the outflowing gas by comparing the measured emission-line flux ratios with photoionization models. The comparison suggests that the five outflowing components are characterized by high hydrogen densities ($\gtrsim {10}^5$ cm${}^{-3}$). Our results imply that the five highly dense gas components may be outflowing with multiple bulk velocities at the innermost part of the narrow-line region in J1010+3725.