Star formation properties and dynamics of Luminous Infrared Galaxies with adaptive optics

TL;DR

This study uses adaptive optics in the near-infrared to analyze star formation, dynamics, and supernovae in luminous infrared galaxies, revealing complex interactions and rare structural features.

Contribution

It provides high-resolution AO observations of LIRGs combined with multi-wavelength data, uncovering new interaction components and rare spiral arm configurations.

Findings

Detection of supernovae in dusty central regions.

Discovery of an unexpected third component in a merging LIRG.

Identification of a rare leading spiral arm structure.

Abstract

Near infrared adaptive optics observations are crucial to be able to interpret kinematic and dynamical data and study star formation properties within the often extremely dusty interacting luminous IR galaxies (LIRGs). NIR AO data are also needed to find supernovae in their bright and dusty central regions and to fully characterize the young stellar clusters found in these kinds of systems. We have used AO in the K-band to survey a sample of LIRGs at 0.1 arcsec (30 to 100 pc) resolution. The data are merged with SALT and AAT spectroscopic follow-up and HST and Spitzer archival imaging. The first AO detected SNe are reported as well as details of the first studied LIRGs. One LIRG showed an unexpected third component in the interaction, which moreover turned out to host the most active star formation. Another target showed evidence in the NIR of a very rare case of leading spiral arms, rotating in the same direction as the arms open.