Optical IFU observations of GOALS sample with KOOLS-IFU on Seimei Telescope: Initial results of nine U/LIRGs at z < 0.04

Abstract

We present ionized gas properties of nine local ultra/luminous infrared galaxies (U/LIRGs) at z < 0.04 through Integral Field Unit (IFU) observations with KOOLS-IFU on the Seimei Telescope. The observed targets are drawn from the Great Observatories All-sky LIRG Survey (GOALS), covering a wide range of merger stages. We successfully detect emission lines such as Hβ, [O iii]λ5007, Hα, [N ii]λλ6549, 6583, and [S ii]λλ6717, 6731 with a spectral resolution of R = 1500–2000, which provides (i) a spatially resolved (∼200–700 pc) moment map of ionized gas and (ii) diagnostics for an active galactic nucleus (AGN) within the central ∼3–11 kpc in diameter for our sample. We find that the [O iii] outflow that is expected to be driven by an AGN tends to be stronger (i) towards the galactic center and (ii) as a sequence of the merger stage. In particular, the outflow strength in the late-stage (stage D) mergers is about 1.5 times stronger than that in the early-state (stage B) mergers, which indicates that galaxy mergers could induce AGN-driven outflow and play an important role in the co-evolution of galaxies and supermassive black holes.

Hard X-Ray to Radio Multiwavelength SED Analysis of Local U/LIRGs in the GOALS Sample with a Self-consistent AGN Model including a Polar-dust Component

“…This supports the idea that the AGNs in U/LIRGs are described by a coevolutionary phase between the host galaxies and SMBHs. Yamada et al (2021) report that AGNs in stage D mergers show multiphase massive outflows at subparsec to kiloparsec scales; that is, UFOs (e.g., Feruglio et al 2015;Tombesi et al 2015;Mizumoto et al 2019;Smith et al 2019), ionized outflows (e.g., Fischer et al 2013;Rich et al 2015;Kakkad et al 2018;Fluetsch et al 2021;Toba et al 2022b), and molecular outflows with velocities above 500 km s −1 (e.g., González-Alfonso et al 2017;Laha et al 2018;Fluetsch et al 2019). As discussed in Sections 6.3 and 6.5, the polar dust luminosities are ∼2/3 × L AGN,int , and the physical sizes increase with AGN luminosity from a few tens of parsec to kiloparsec scales.…”

A Machine-learning Approach to Assessing the Presence of Substructure in Quasar-host Galaxies Using the Hyper Suprime-cam Subaru Strategic Program

“…The initial interaction through tidal torques induces gravitational instabilities (e.g., matter asymmetries) within each galaxy that then cause gas inflow to the nuclear regions that triggers a burst of star formation and accretion onto an SMBH (e.g., Mihos & Hernquist 1996;Hopkins & Quataert 2010;Moreno et al 2015;Blumenthal & Barnes 2018). Numerous studies, both theoretical and observational, have provided substantiating results from various perspectives in terms of galaxy merger state and AGN demographics (e.g., Ellison et al 2011;Silverman et al 2011;Mechtley et al 2016;Goulding et al 2018;Ellison et al 2019;Toba et al 2022).…”