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Paper: Morphology of Luminous Infrared Galaxies
Volume: 396, Formation and Evolution of Galaxy Disks
Page: 247
Authors: Pizagno, J.; Vavilkin, T.; Evans, A.; Mazzarella, J.; Howell, J.; Armus, L.; Surace, J.; Chan, B.; Barnes, J.
Abstract: At luminosities above 1011.4 L, the space density of luminous infrared galaxies (LIRGs) exceeds that of optically selected galaxies. LIRGs are primarily interacting or merging disk galaxies undergoing enhanced star formation and active galactic nuclei activity, possibly triggered as the objects transform into massive S0 and elliptical merger remnants. We aim to test this evolutionary scenario. We have obtained HST/ACS imaging of 88 LIRGs with LIR > 1011.4 L, selected from the IRAS Revised Bright Galaxy Sample (60 μm flux density > 5.24 Jy). This sample is ideal due to the proximity and brightness of the galaxies, given HST high sensitivity and angular resolution. We are studying the detailed structure of LIRGs sampling all stages of the merger process. Initial morphological analysis shows that single-nucleus LIRGs have an average concentration index (ratio of radii containing 90% to 50% of the flux) of 3.05, similar to elliptical galaxies which have concentration indices greater than 2.9. The analysis is complicated by extended tidal features.
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