Presentation #342.04 in the session “Galaxy Evolution & Populations”.
We use Hubble Space Telescope (HST) data to investigate a previous analysis of the shocked gas in nearby luminous infrared galaxy merger NGC 3256. Utilizing the Wide-Field Spectrograph (WiFeS), Rich et al. 2011 found that NGC 3256 contains starburst and shock excitation in its Interstellar Medium (ISM) likely resulting from on-going merger activity. Therefore, the ISM of NGC 3256 is an ideal source for investigating the feedback from merger driven shocks. During the merger process, tidally induced gas flows and galactic winds give rise to shock excitation throughout the ISM. In order to quantify the impact of shock excitation on the ISM we must carefully distinguish star forming regions from locations that show evidence for shock excitation. The spatial resolution of previous studies using WiFeS limited our ability to distinguish ionizing mechanisms. Here we used high spatial resolution optical image data from the HST and compared that to the spectral data from WiFeS. We plan to observe emission lines such as [Hα], [Hβ], [O I], [O III], [N II], and [S II] present in the ISM of NGC 3256. From these emission lines, diagnostic diagrams can be constructed for specific emission line ratios separating the shocked regions from star forming regions. Comparing shocked regions between data sets allows us to test the previous hypotheses, ultimately allowing us to more accurately resolve shocks and star forming regions in galaxy mergers.