High-Resolution Optical IFU Spectroscopy of the Complex Galaxy Merger II Zw 096

TL;DR

This study uses high-resolution optical IFU spectroscopy to analyze the complex merging galaxy system II Zw 096, revealing multiple interacting galaxies, high star formation, and evidence of a heavily obscured AGN, providing new insights into galaxy evolution.

Contribution

First detailed high-resolution spectroscopic analysis of II Zw 096, uncovering multiple galaxy components, their interactions, and the presence of a heavily obscured AGN.

Findings

Identification of three or more distinct galaxies within II Zw 096

Detection of complex kinematics and ionization structures indicating active star formation and shocks

Evidence of a heavily obscured AGN in the D1 region

Abstract

Luminous and Ultra-luminous IR galaxies ((U)LIRGs) are critical for investigating feedback mechanisms due to a combination of intense star formation (SF) episodes and active galactic nuclei (AGN), particularly in the context of complex galaxy interactions. We conduct a detailed analysis of the II ZW 096 merging system using the Multi-Unit Spectroscopic Explorer (MUSE) on the Very Large Telescope (VLT), combining high-resolution Narrow Field Mode (NFM) and large-area Wide Field Mode (WFM) observations. We mapped the morphology, kinematics, and ionizing radiation of the system's gas by fitting atomic emission lines and the optical continuum. We identify three or more distinct galaxies within II ZW 096, revealing rotational patterns and complex interactions consistent with a collapsing small galaxy group. The kinematics and ionization structures suggest high star formation rates and shock-driven processes, which align with this proposed scenario. Focusing on the D1 compact region, which contributes 40-70% of the system's IR emission, and combining information from archival multi-wavelength observations, we find strong evidence of a heavily obscured AGN powering it. Our analysis of the internal structure, interactions, and merger state of II ZW 096 offers novel insights into the galaxy evolution processes in this dynamic and highly chaotic system