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

TL;DR

This paper reports the discovery of a complex, multi-component ionized outflow in a dust-obscured galaxy, revealing high-density gas with diverse velocities near the galaxy's nucleus.

Contribution

It presents the first detailed analysis of a five-component ionized outflow structure in a dusty active galactic nucleus, using emission-line diagnostics.

Findings

Five narrow outflow components with velocities from -1475 to +507 km/s.

High hydrogen densities (>10^5 cm^-3) in the outflowing gas.

Multiple velocity components suggest complex outflow dynamics near the nucleus.

Abstract

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.