CfA OIR Division Lunch Talks
Wednesday, March 26, 2014, 11:00 am, Pratt Conference Room

Lesser role of mergers in high-z IR-luminous galaxies?

Chao-Ling Hung (IfA UH, SAO)

Galaxy interactions/mergers are known to dominate the population of infrared luminous galaxies in the local universe. However, it is unclear if this is still the case at high-z. To test how the relative importance of galaxy interactions varies across cosmic time, we carry out a comparison of optical morphological properties between local and z~1 (U)LIRGs. To control for potential biases, we use the same sample selection, morphology classification scheme, and optical morphology at similar rest-frame wavelengths. In this talk, I will show that there is no strong evolution of merger fraction in (U)LIRGs at least out to z~1. In parallel, we test the robustness of the merger/disk classification scheme developed based on the kinematic properties of high-z galaxies. We construct an artificially redshifted sample using local IR-luminous galaxies with known merger status from HST images. In this talk, I will discuss if the kinematic classifications are able to accurately determine the merger/disk nature of these artificially redshifted galaxies. I will also discuss how these results may affect the interpretation of the role of mergers in high-z IR-luminous galaxies.