Ionized Gas Outflows in Infrared-bright Dust-obscured Galaxies Selected with WISE and SDSS

Abstract

We present the ionized gas properties of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme optical/IR color, (i − [22]) AB > 7.0, selected with the Sloan Digital Sky Survey (SDSS) and Wide-field Infrared Survey Explorer (WISE). For 36 IR-bright DOGs that show [O iii]λ5007 emission in the SDSS spectra, we performed a detailed spectral analysis to investigate their ionized gas properties. In particular, we measured the velocity offset (the velocity with respect to the systemic velocity measured from the stellar absorption lines) and the velocity dispersion of the [O iii] line. We found that the derived velocity offset and dispersion of most IR-bright DOGs are larger than those of Seyfert 2 galaxies (Sy2s) at z < 0.3, meaning that the IR-bright DOGs show relatively strong outflows compared to Sy2s. This can be explained by the difference of IR luminosity contributed from active galactic nucleus, L IR (AGN), because we found that (i) L IR (AGN) correlates with the velocity offset and dispersion of [O iii] and (ii) our IR-bright DOGs sample has larger L IR (AGN) than Sy2s. Nevertheless, the fact that about 75% IR-bright DOGs have a large (> 300 km s −1 ) velocity dispersion, which is a larger fraction compared to other AGN populations, suggests that IRbright DOGs are good laboratories to investigate AGN feedback. The velocity offset and dispersion of [O iii] and [Ne iii]λ3869 are larger than those of [O ii]λ3727, which indicates that the highly ionized gas tends to show more stronger outflows.

Discovery of Dying Active Galactic Nucleus in Arp 187: Experience of Drastic Luminosity Decline within 104 yr

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Discovery of an Extremely Luminous Dust-obscured Galaxy Observed with SDSS, WISE, JCMT, and SMA

“…That unusual spectrum could indicate that ionized gas is outflowing from the ERQ. Such phenomenon is often observed in red/dust-obscured AGNs (e.g., Zakamska et al 2016;Toba et al 2017c).…”

Discovery of a strong ionized-gas outflow in an AKARI-selected ultra-luminous infrared galaxy at $z$ = 0.5

“…If we assume the [OIII]-based L AGN , then J0916a (shown as open stars in Figure 17) becomes close to the most luminous high-z QSOs with the most powerful outflows in theĖ out -L AGN diagram. The Eddington ratio λ Edd ≡ L AGN,[OIII] /L Edd ∼ 10 is similar with that of the DOGs/ULIRGs with super-Eddington accretion (Kawakatu et al 2007;Assef et al 2015;Toba et al 2017). The [OIII]-based L AGN requires that the entire IR luminosity is owing to AGN, which is hard to be reproduced by the current SED fitting templates, where the FIR peak is mainly contributed by star formation heated dust.…”