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oai:docta.ucm.es:20.500.14352/451182023-08-26T17:25:04Zcom_20.500.14352_14col_20.500.14352_15

Shi, Yong Rieke, George Lotz, Jennifer Pérez González, Pablo Guillermo 2023-06-20T04:16:35Z 2023-06-20T04:16:35Z 2009-06-01 0004-637X 10.1088/0004-637X/697/2/1764 https://hdl.handle.net/20.500.14352/45118 http://dx.doi.org/10.1088/0004-637X/697/2/1764 http://iopscience.iop.org/ We present a morphology study of intermediate-redshift (0.2 < z < 1.2) luminous infrared galaxies (LIRGs) and general field galaxies in the GOODS fields using a revised asymmetry measurement method optimized for deep fields. By taking careful account of the importance of the underlying sky-background structures, our new method does not suffer from systematic bias and offers small uncertainties. By redshifting local LIRGs and low-redshift GOODS galaxies to different higher redshifts, we have found that the redshift dependence of the galaxy asymmetry due to surface-brightness dimming is a function of the asymmetry itself, with larger corrections for more asymmetric objects. By applying redshift-, infrared (IR)-luminosity- and optical-brightness-dependent asymmetry corrections, we have found that intermediate-redshift LIRGs generally show highly asymmetric morphologies, with implied merger fractions ~50% up to z = 1.2, although they are slightly more symmetric than local LIRGs. For general field galaxies, we find an almost constant relatively high merger fraction (20%-30%). The B-band luminosity functions (LFs) of galaxy mergers are derived at different redshifts up to z = 1.2 and confirm the weak evolution of the merger fraction after breaking the luminosity-density degeneracy. The IR LFs of galaxy mergers are also derived, indicating a larger merger fraction at higher IR luminosity. The integral of the merger IR LFs indicates a dramatic evolution of the merger-induced IR energy density [(1 + z)^~(5-6)], and that galaxy mergers start to dominate the cosmic IR energy density at z greater than or ~ 1. eng open access Role of galaxy mergers in cosmic star formation history journal article